This is what we start with, a pair of GTX660's
And this is the GTX750's in their place.
Here are some GPU-Z screen shots. The first showing the card details
And this one showing it rather maxxed-out while running two Seti@home Multi-Beam cuda 50 work units.
They are certainly running a lot cooler than the GTX660's that were in there before. They also appear to be quicker but it could be the work units which vary in the amount of processing required.