I've been pimping this since 5.0 was announced.

Some people, particularly those with less experience found a particular test order helpful, which  grouped overlapping or coordinating sections.  Completing a hybrid ARE would defeat this seeming advantage.  Otherwise, If you have sufficient experience it shouldn't matter much. Save yourself $225.

Going with NCARB's plan is the best way to not have to re-take test subjects you've already taken (or "lose credit" for them).  In the last transition to the current version there were many people who ended up taking several more tests than they'd originally planned for because they didn't pass the full collection necessary in the old system to equal a division in the new system (in some cases this meant up to 4 previous divisions "lost").

But that said, do keep an eye on NCARB's transition charts as the new test date comes closer.  In the last major transition they subtly changed the charts as the transition neared, without issuing any notification that they'd done so - so some who'd charted their course based on the original ncarb web posts and postcards were surprised to find that they were off course anyway.

I looked into this quite heavily as I was preparing to start testing. The typical grouping for the exams to help with overlapping and coordinating content (that Jerome S mentions) includes grouping CDS, PPP, and SPD. If you can pass those under 4.0 and then transition to 5.0 you only have two divisions in the new system left to take; Project Planning & Design and Project Development & Documentation. The credit model shows that this would take care of any other overlapping or coordinating content with minimal repeat of division content in 4.0 you've already passed.

Pros are definitely enticing where you only have to take 5 exams instead of 6 or 7. You can consequently save money on the exams because you are taking less. You also won't have to deal with NCARB's software for the vignettes because those are going away under 5.0 as well.

The only real downside I could see is that you are going to be testing under a new version of the test. While this doesn't seem like much, to me it is fairly big. You will be a guinea pig for the new system. You will not have the collective knowledge that exists for taking and succeeding on the 4.0 divisions like there currently is. Generally pass rates fall after a new version is released which means that pass rates are at the highest right now for 4.0. What they will be for the beginning of 5.0 is completely unknown. There has been disagreement with what sort of study materials and testing help will be available for 5.0. Right now there is a lot of help for 4.0. 

The other thing to consider is that 4.0 will be available for testing until the middle of 2018. There is plenty of time to start testing now and finish before you are forced to transition over to 5.0. 

Personally, I decided not to wait for 5.0, and to just finish everything under 4.0. My firm reimburses me for the cost of the division when I pass it, so cost isn't really an issue. I'm generally a good test taker so taking the tests themselves doesn't phase me. 5 or 6 or 7, doesn't really matter to me. The vignette software sucks, but it's manageable and there is plenty of help out there on arecoach's forum, as well as other resources.

I'm starting with CDS, PPP, and SPD (according to the credit model) so that if I have to transition, because I can't pass everything in time for 2018, I'll get credit for a few of the 5.0 divisions. I doubt that will happen for me though. I'd have to start failing divisions and take time off from testing in order to get into that sort of situation.

It also allows me the option to change my mind later when 5.0 comes out. To me that's probably the biggest take away from this. Take the 4.0 divisions that on paper will give you the biggest bang for your buck in 5.0 ... hold off on taking SD for now.

Bloopbox's advice is good. I'll keep an eye on that if I start failing divisions. 

It's worth considering that pass rates for the first year of new ARE versions are terrifyingly low. 20-30% is what I've heard from the 3.0 to 4.0 switch.

Taking 2 more tests doesn't seem like as much of a burden if you're more likely to pass all 7 on the first try.

^ seems like it was closer to 50-60% from what I could find. NCARB doesn't have numbers that far back on their website anymore but luckily nothing ever goes away online. Compare that to pass rates for all seven divisions for 2014. Four of the seven divisions are at 68% and higher. None of them are below 62%.

Yes, after the last transition the pass rates dropped a bit in the first year - but not all that much.

If you're planning to follow NCARB's transition plan in order to take the least number of tests, then I'd suggest saving screen shots of the transition chart.  Last time they played some shenanigans with the transition charts mid-transition, and didn't seem to think anyone would notice.  

Also consider carefully whether you want to risk scheduling tests for shortly before or after the transition.  Back in the 2004 transition they cancelled about a month's worth of already-scheduled tests right before the transition forcing people who thought they could get their last test in before the transition to wait until the new version came out.  There were also some serious computer glitches when that new version came out - example: there was a required piece of furniture missing from one of the graphic vignettes, so everybody who initially encountered that vignette got a fail letter.  That was also the year of the infamous "cut score study" in which they held up the scores from all tests taken from February thru May until late June, without telling candidates they were planning to do that, and sent a memo to all state boards instructing them not to tell testing candidates what was going on.

I stand corrected. I didn't have a direct source but I'd heard that number tossed around by multiple people in the past. No clue where they got it...

Either way I'm gonna stick with 4.0

Bloopox ... keep the advice coming. This is great information. 

To my point above about focusing on passing the 4.0 divisions that will give you the most bang for your buck under 5.0 ... play around with the transition calculator NCARB has. You can quickly see that passing CDS and PPP under 4.0 will give you credit for three divisions of 5.0. To me, these are 'must pass divisions' in 4.0 if you want to transition and do a hybrid approach.

You can play around with other combinations and end up taking 3 and 4 divisions in 4.0 and not receiving credit for anything under 5.0. For an extreme example; you could take 5 divisions (PPP, BDCS, SS, BS, and SD) under 4.0 and get absolutely nothing for 5.0.

If you start testing now, make it count for something for the rare chance that the unthinkable happens and you are forced to transition to 5.0.

According to this press release about the "cut score study" back in 2004, this is something they do when new passing standards are established. They mentioned that it had been 7 years since it had been done for the ARE. Any idea if they've done it again since 2004?

If not, it seems like it might happen again with the release of 5.0.

Edit:

Based on this comment from Jared N. Zurn, the cut score was last established in 2008 when 4.0 was released. 

Yes they've done it at least twice more recently.  One was a more limited study, of just one division, and then in 2008 they did another more extensive one, but that time they didn't keep it a secret that they were doing it, and I think they even offered some kind of incentive to some number of people who dared to take the test during the study, in order to make sure they had a large enough pool of tests to study.  I don't think scores were delayed for as long then as in the 2004 debacle either.  I would guess that they'll do it again when the new version rolls out.