Lower temps. tend to give you a drier, thinner beer (read: higher ABV), also hops utilization is effected. I made two-five gallon batches of an identical recipe for my APA. As an experiment, I mashed one at 154F and the other at 149F. Both pre-boil and OG's were within .001. Both used S-05, both fermented side by side at 66F. The APA mashed at 154F finished at 1.013, the APA mashed at 149F finished at 1.008. Both were delicious, but different.
I realize that I didn't brew these in a lab environment, so some other factors might have effected the outcome, but you can see the general idea here.