K.R.
My good friend used Dr.Brown's as a last resort to help her daughter's gas. They worked, but she hated cleaning them and would put it off until she only had one clean bottle left and it was a neccessity to do the despised task!
I have had babies in my care that were pretty gassy on regular bottles and when I switched them to drop ins it helped tremendously! If I were you I would start with drop ins, and if you are still having problems, then switch to Dr.Browns.