Personally,i prefer bestmixer,to me atleast it seems safer,i have no problem paying the 0.5% fee (for me)to make sure my coins are properly mixed.Plus i hate how on chipmixer if you said 0.05691 you get a 0.05 chip and thats all.
Overall it is BestMixer for me 100%
You should be getting a 0.032
BTC chip, a 0.016
BTC chip and a 0.008
BTC chip. (you lose the 0.00091
BTC as that can't fit in a 1 mBTC chip). 0.05
BTC chips don't exist and never have.