Nope... not really...

Number of cores.... cache size proportion, amount of RAM and Graphics card and its graphic memory makes more difference. Optimization of the operating system.... cleaning up registries, defragging and getting rid of adware/spyware/malware and viruses/trojans/rootkits and worms from your computer will make a bit of difference in performance. 

.3 GHz but same number of cores and same size cache won't make much difference but if you are buying a cpu, think of the dollars per GHz you are paying and number of cores. A 4 core cpu at 3 GHz is like a single core at 12 GHz (sort of....)

Get the most bang for your dollar's worth. Most L1 cache and most L2 cache and L3 cache (if there is any... anymore). Since you are comparing an i7. Compare cache between the two. We are talking like Sandybridge vs. Ivybridge. 

Since you are really comparing entire laptops.... you have to compare the GPUs and how much graphic memory it has. The more, the better. You are also comparing system memory and hard drive capacity. The extra $180 maybe worth it if you are getting a better graphic GPU with more performance power in the GPU processing ability, graphic memory capacity, video resolution options, etc. Take into consideration screen size, too. What is in the whole system package.

If it is just the CPU difference.... I would be hard pressed to pay an additional $180 for 0.3 GHz unless I was getting 6 to 8 cores instead of 4 cores and the slightly higher Ghz rate. That would be worth the investment. If not, then I would likely decline paying the extra $180 and use that on something else like upgrading RAM or upgrading the video RAM in the GPU from say 1 GB to 2 GB or 2GB to 4GB. Being a laptop... I suspect it being around 1GB but upgrading it to 2GB would help. Upgrading system memory from say... 8GB to 32 GBytes would help as well.

If I am going to invest an extra $180 into the computer, I would look at graphic card/graphic memory and system memory or upgrade by number of cores from 4 to 6 or 8 core. 

4 core at 3 Ghz is kind of like a 12 Ghz single core. I said sort of. It isn't exactly and I agree but from a basic performance perspective you need to drive a single core Pentium 4 at 12 Ghz to get about the same effective computing performance as that quad-core. Because the cpu is at 12 Ghz not the rest of the computer. 

I can theoretically have four 4 MHz 6502 on a cartridge connected to a 1 MHz C64 motherboard or I have a single 16 MHz 6502. It is about the same effective performance because the cpu or cpus are still connecting to a 1 MHz motherboard. The same idea with 3 GHz CPU or cores connected to a 1 GHz motherboard bus. 

We know the Intel cpus are clocked in multiples of the motherboard system bus clock.

I wasn't implying it would be literally the same. The reason intel doesn't introduce 12 GHz processors is because the interconnects will act like transmission lines and there would be arcing between interconnects on the die. The reason for this has to do with silicon semiconductor technology. They don't reliably work at clock rates much higher than 4 Ghz. Once you are at this frequency level.... it gets risky especially at such small interconnect to interconnect spacing. 

I understand your point in technicality. Yes, it wouldn't quite be the same as a 12 GHz computer because the multiplier of the cpu clock to system clock is between 1:1 to 8:1 ratio depending on CPU core clock and and motherboard clock. We have had 20:1 ratio of the cpu to system clock on the Commodore 64 via a 65c816 on a cpu accelerator module (superCPU by CMD) clocked at 20 MHz while the system bus was 1 MHz.

A typical 12 GHz computer would be connected to a 3 to 6 or 8 GHz motherboard clock.

I didn't want to get into this stuff. My past education and training includes computers and software & hardware development. 

What I am saying is a single core would roughly need to do just about as much as the 4 core. However, yes, many computer software isn't optimized for multi-core. It would take a 12 GHz single-core processor to do the computational capacity of a quad core at 3 Ghz assuming software optimized for single and quad-core processing. The few percent of overhead of process handling of a quad-core is minimal.

So a 11.3333 to 11.6666 Ghz processor.... wow. Of course, I was assuming the motherboard being the same. I doubt we can drive a single core 3 GHz Pentium to 12 Ghz without that going up in smokes because intel/amd processors can't be overclocked that much. 

That's beyond the scope of this topic..... really.

Of course, today motherboards aren't even 1 Ghz. It's more like 66.6667 or 133.3333 MHz with double data rate and AGP like techniques being used because the physical geometry of the board is too big to actually clock at 1+ GHz.

That's a laws of physics barrier for the materials used.

There's alot involved..... That is beyond the scope of the thread. 

Today's computers are taking more and more Amiga like approaches with the graphic cards while also employing multi-core cpus because they can't make silicon cpus as complex as an intel / amd processor to reliably operate at clock rates much higher than 6 GHz. Above 4 GHz and things are a bit risky. The interconnect to interconnects starts generating an electron field that because of how close the interconnects are to each other.... they short out. Hence, a dead chip.

Modern PCs are taking the idea from Amiga computers to have custom video and other hardware that does certain tasks better and more efficient than the CPU. Part of the advent of "hardware acceleration" in graphic cards and the modern high power GPUs which are engineered to process graphics much more efficient than the x86/x86-64 processor core.

​I wasn't suggesting Mac or Windows.