From the looks of this GTX 750 Ti on Collatz, expected results should be around 300k/day:
http://boinc.thesonntags.com/collatz...?hostid=133526
That's 50% more production than the HD 7750 (currently the fastest AMD card that doesn't require auxiliary power) with 20% less power draw.
I'm hoping to get my 750 Ti up and running tonight or tomorrow morning and start putting it to the test!