Yes, and often times I even cycle through more than six. In White 2 I went around swapping between Samurott, Durant, Cinccino, Excadrill, Scrafty, Sawsbuck, Beartic, Galvantula, Reuniclus, and Swanna. Audino training makes it really easy to bring a new member up to snuff.
Admittedly those last two were only because I realized I had a pretty huge Fighting weakness and I'd need something to go up against Marshall with, and it's nice having something that can Surf and Fly. I don't even really like Swanna...
http://i.imgur.com/z7h3ZVX.jpg "First time I got punched in the face, I was like "oh no", then I was like "this is a story"."
Four for a first time, was less if im just stomping through the second/third version to unlock stuff. I have never been able to field a team of six where I was happy, but then I have serious sometimes. Dead weight garbage like Serperior or Musharna, Pokemon who had to stall things to death or are super slow or have garbage move pools just kill me to use in-game. I have to have stuff like Infernape or Excadrill or Gyarados.
Official Togekiss of the BW2 Boards Plothooker - www.plothook.net - Get Hook'd