The pinky strain depends on your compatibility with the keyboard. I recently bought an expensive Microsoft ergonomic wireless keyboard (because my old dell one was too noisy) and while it's great for typing, it's a pinky-killer.
The problem with this one is that the Ctrl button is too close to the Z button. I have to bend my pointer and my pinky until they almost touch.
I had no problem with the dell doing this, but with the new microsoft keyboard I'd better learn how to use another finger for the Z.
After just a couple of days I'm feeling pain in the articulations. I do 3D and I probably hit Ctrl, Shift, alt, Z, X, C, V combinations about 20 times a minute. Funny I never had a problem with my dell keyboard (over 3 years of use). I guess "one-size-fits-all" doesn't go with keyboards.
Bottom line - try to find a quality keyboard based on reviews. Once bought, try to adapt to it if it doesn't feel natural. Try switching fingers (hard, I know) and ultimately, if you can't get used to it, buy another one. No point in sacrificing your health over a few $$$. A bottle of painkillers may cost as much as a proper keyboard :)