here's my experience with cam gears...
spoon/toda are badass...as you get what you pay for!
now, skunk2 gears work well, although under extreme conditions the gears can sometimes expand, causing the timing belt to become tighter and this can cause a motor to seize, bad!!!!!!!!!!
but this is in rare conditions, and unlikely to happen, although i'd check the tension of your timing belt from time to time...
aem gears...yes i worry about them slipping, however when torqued correctly they can be reliable...
for a daily driven setup i'd go with skunk2 gears. personally, i'm going with toda cam gears when i have the money, of course there are others out there including endyn and str which are also supposed to be good. i can't comment on these, because i've never used them.