From my experience, SU! eyelets are the best !!! When I first tried using eyelets, I was always so frustrated with the way they cracked or how some of them would not bend no matter how hard I pounded !!!
With the small SU! eyelets, I hit them 3 times with the hammer and setter (not very hard at all) and then use the hammer to flatten the back out. The gold ones seem to be stiffer (not sure if that is the best way to describe it), but even then I hit them about 5 times first.
I agree that $12 isn't bad for 400 great quality eyelets !!!