It most certainly does affect the taste! I found that, for me, anything over about 12mg and I could really taste the nic. It can be a pretty harsh taste too... depending alot on the nic that is being used. You just need to try different levels and see what works/tastes best to you. The other main thing affecting taste is the PG/VG content. PG tends to carry flavors better... and VG tends to mute them a bit.