That's pretty poor speeds anyway.  Both of my 6x rig's are ~1750-1850 (I keep it at 1750, as one or more of the cards doesn't like my modest OC and I haven't figured out which one yet, tho it runs stable 12+ hours before acting up.  At 1750-1800 it doesn't have any issues) and temps aren't even moving over 55 (no case, just a desk fan).  I suspect improvements to cudaminer and possibly nvidia drivers will increase that slightly as well.  So far I'm pretty happy with the 750 ti's (power draw) over my 290's, 290x's. 

Need to take the rig to my kill-o-watt tho still to really determine the difference in cost @ wall.

I'm excited for the next release in the series.  Anyone else noticed that these have incredibly low reject rates?