I think you made a good call, unless you have $300 lying around that will just be used for beer money. The pros to the new penryn MBPs include the increased video ram (but you don't do anything graphics intensive), 17" LED screen (you're getting the 15", so you'll have an LED screen anyway), pretty similar CPU performance for the base model based on benchmark tests (comparing 2.2 GHz w/ 4mb Cache to 2.4 GHz w/ 3mb Cache), larger hard drive (this could be useful), and multi-touch (I actually think this is very useful and will be fully utilized with software updates, but the SR MBP you're buying doesn't have the hardware to ever have multi-touch). Other things of note, the Penryn chip should run cooler and more energy efficient, meaning less burn if you keep it on your lap and better battery life. Also, as said before, the penryn chip utilizes a new set of code instructions, and future programs that are written for these will potentially run up to 40% faster. But, that is all dependent on if you ever use any of those yet uncreated programs...
So, the choice is yours. But if money is a factor, and that appears to be the case, then I concur with your decision.
-Ado