Formula Transition questions

fishybride82

So on Tuesday I will meet my BF goal of 3 months and to be blunt I have no interest in continuing. Tomorrow night we will probably give DS his first bottle of formula (DH and I both like to be around for transitions).  We were going to start with the dinner time bottle and go from there.  I know we should just do one bottle at a time for a few days.   We are starting with Similac Advantage since that's what we have to most samples of.  My question how long does it usually take for a child to adjust to a change like this. I don't want to think there is a problem and jump from formula to formula because that might be worse. Should I continue with one kind of formula for a week? Two weeks? 

Anyone that has done this transition before have any advice?   Thanks.