VRay for max is really good, really fast, and relatively easy to use. By easy, i mean that i've found it to be easier to pick up than Mental Ray. I haven't really used Brazil or any of the other GI renderers, so i can't give you a fair comparison to them.

vray is apparently the fastest GI renderer out there. another advantage is that there's tons of tutorials and resources on the web, making it easier and quicker to train yourself.

i've downloaded and played with the vray for rhino demo a bit. its similar to the max version, just maybe not quite as user-friendly. but thats probably more because of the slightly clumsy rhino interface than anything else. just setting up a camera view and lights in rhino is a bit of a task...

to be honest, just for the ease of use of the max material editor and camera setup, i'm still sticking with exporting rhino models to max for renderings. i'm using nPower's PowerTranslators for the export. it's a whole lot more accurate than a 3ds or dwg export...

none of the GI programs are 'easy' to learn. Personally, I didn't find VRay easier to use than Final Render, but that's just me. fR, I believe, is the fastest out there but can take a little longer to setup (or so I hear, again, I haven't found that). Just too many variables to really declare one faster, easier or better.

Not much help, eh?

I had to decide on one renderer to peruse so that I could progress my skills, so I chose VRay with MAX. The main reason, as TT explained, was the amount of support and tutorials available. I also appreciate the VRay material libraries that are provided on their web site.

I am going to stick with VRay, however I would like to hear if anyone else has any comments for or against. anyone use Maxwell?

maxwell is coming along, but it's still dog slow, and for some reason the quality seems to go down as they add more features. Alot of the initial promise seems to have faded, but for certain things it's quite good.

i've been trying to figure out for a while what is the best GI solution; Vray or Mental Ray, and this has been a topic of discussion for some time in our office, and we've recently consulted 'professional help'...here's the conclusions:

when used correctly Vray is faster than Mental Ray, hands down. (on that note, MR is one of the slowest render engines around)

Vray was invented by one person, Mental Ray has been developed over the years by a team of german software engineers. (for what its worth)

Mental Ray is much more sophisticated (thus more complicated and time consuming) in many aspects as a render engine than Vray. However sophistication offers more control, detail, depth, etc...

Mental Ray's virtue lies in it's shaders. MR shaders offer many great realism in materials. In comparison, Vray materials are relatively dumb.

Mental Ray lights, when fully understood, offer a great deal of customization and control. Vray lights are fairly simple.

The question is -do you as an architectural renderer need all of this sophistication? Are you wiling to accept the learning curve and longer render times for a slightly better result? And is the end result really that much better?

Most likely not.

The main advantage for our firm is that Mental Ray comes standard with Max...thus we don't have to buy addtional licenses for a render engine. Also, we can toss our MR jobs on the network render farm b/c it's not a plug-in.

V-Ray is plenty complex for me.

And the renderings are 100 times better than what I was capable of before in Flamingo (and formZ if you want to go back that far). So from my perspective, that of someone who never touches Mental Ray, I am blown away by V-Ray's performance. (But don't get me wrong. What I have seen from Mental Ray is amazing.)

As a Beta tester for V-Ray for Rhino, I have been able to watch the development progress firsthand, and I have little doubt the Rhino version will catch up with the Max version as far as ease of use.

wangsta - the cost for licensing is much cheaper with both fR and VRay than with MR. I haven't kept up with MR's licensing, as they've surely felt the pressure and reduced their ridiculous limitations, but last I knew VRay and fR could be used virtually on an unlimited render farm, whereas MR limits the number of processors and charges you for additional licenses.

New versions of each, including MR, are on their way. It'll be interesting to see how it plays out.

The reason I want a built in renderererer is that I hate changing the model, then having to reassign materials etc after exporting again. It also seems that going from NURBS to Mesh requires a ton of extra work in the model because MAX doesn't deal with surfaces the same way. For example, the infamous bowtie effect. Sometimes you just need a surface to be seen or cast a shadow, but not a model of the whole thing. That is a pain when exporting. Architectural Desktop to Viz render is actually really nice since it is so easy to update your model and not lose materials etc. But modeling in CAD (for me atleast) sucks. I really like MAXs material editor, you are right with that. It's way better. I do like 3Ds Max's camera. The clip plane is nice. I don't find setting up cameras or lights to be that difficult in Rhino. I need some time to 'speriment with VRay. Maybe in my jet lagged week before class starts.

Also, I played with Maxwell for like 2 hours and it was disappointing. SOOOOO slow. I tried Maxwell vs. light tracer. Light tracer was faster and easier and looked better. Maxwell's interface is terrible.

Vray Advanced 1.5.0.R2 for 3ds max 8 was released a couple of days ago following Siggraph.
We use Vray a lot more than any other GI engine. I've used Mental Ray, Final Render and Brazil on some projects but usually only use other GI rendering engines when a client requests it. We never bothered with Maxwell which I though was a waste of time (at least for now). I've found Vray and FR to be the easiest to use of the ones I mentioned with Brazil and MR coming second and third respectively. Although Mental Ray has been around for a while and does a very good job, it really takes a decidated team of people to work with Mental Ray for it to be used at it's best.
Like TickerTocker, I'd rather use PowerTranslators to bring Rhino files into 3ds max then render in Vray.

Where can I find PowerTranslators for the export of Rhino files to 3dMax. Is it a pluggin? How and where can I get it?

You could also look into Okino Polytrans.