I find I get similar results. I have a QHY5L-IIc which is supposed to do 30fps @ 1280x960 (according to this:
http://www.gamaelectronics.com.au/files/QHY5L2.jpg)
In EzPlanetary I get consistently 14-15fps. It's definitely not a hardware speed issue as it's the same on both my laptops. Both have SSDs and they're both very fast laptops, especially the new one. Same results on Win7, Win8 and Win8.1.
I've tried FireCapture and I get the same 15fps.
I've tried SharpCap and I've seen higher rates in that, up to 24fps, but it's inconsistent.