N.H.
Hi, Jean. I've also heard that you should stick with the brand the baby started on, but I don' think that's for everyone. I mostly breastfeed, but do supplement with one bottle each weekday of formula. At the hospital, my baby was jaundiced when he was born, so we had to give him an ounce a day of formula to help flush out the bilirubin, and the hospital gave us Similac. Once the jaundice cleared up, we didn't have to supplement anymore.
Once I started back to work and pumping for his day care, I realized I would need to supplement with the one bottle a day (just don't get enough when I pump), I read a lot about different ones and really liked the idea of the Carnation/Nestle Good Start. I think it was the "comfort proteins" that got me. In any event, my little boy loves the Good Start and has had no problem switching. Both formula brands we used are milk-based, so I think as long as you are consisntent with the base (milk vs. soy), you should be fine.
Let me know how it goes. Good luck!
N.