I went with the low-end 15" model, just as I did the last time I bought one - and there was a similar price discrepancy. The higher end CPU came with a slightly better GPU as well, but that didn't phase me. I do agree with the sentiment of budgeting for the best computer your money can buy, but in a laptop, I think you also have to consider battery life and heat.
For me, it was a no-brainer. I seldom game on my laptop, and I don't believe the difference of a few hundred MHz really makes a difference in real life. You have some heftier needs than I do as it seems you're running some power-hungry apps. But I really think you're looking at just a few less seconds of rendering time. If that kind of time difference is worth $300 to you, then by all means, go with the higher end CPU. But I think in general, the MacBook Pro is very well equipped, even in lesser trims. At the end of the day, it all comes down to how you will use the machine. If it's going to replace a desktop for you, then it might be worth it. If it's going to complement one (as it does for me), then it's not quite as important.