I'm going to build a big cluster based on gtx480s and not c2050s  - your own benchmarks show why!  little gain over c1060... 
(everybody knows that 480s are almost 5 times more expensive. So even the compute-bound applications will 
benefit, and bnadwidth-bound by a huge factor. )

the fact that 480s have half the mem of 2050s is not so crucial. 