A $300 jump to FQ is pretty low for it. I'd definitely go for it. I've stayed at all the moderates and FQ really is wonderful. FQ's bus situation can be a toss-up. Last October I didn't share a bus going to the parks once. I believe I did a few nights on the way back, but the bus stops at FQ first on the way back.
CSR was nice, but was huge. The pool is definitely better. The pool bar is also open for breakfast so if its closer to your room than the food court, you can go there and fill up your mug. However, I wouldn't take a $500 hit to go with CSR, especially with the construction.