We are using Similac...we have the sensitive that we are feeding him most of the time now but we are slowly switching to the Similac Advance (blue & white container).
My sister prefers Enfamil...we never tried it so, I don't know about it.
we keep the ready-made bottles handy for when we need to go somewhere. We took him to my grandmothers yesterday and took those so he could eat during our visit. He eating 2oz so it works for now. We had the pre-made formula in the larger container for middle of the night feelings...it was easier than measuring out the powder :) we ran out but I'm thinking about getting more tomorrow :) I'm all about keeping it simple at 3am