I do both, I multibox my shammys, locks, mages, and hunters and mix them as well, but I also raid on my main hunter solo and pvp on it solo, and I pvp on shammys boxed... just depends what I am wanting to do and achieve. For instance raiding and doingheroic mode,cannot box it, so its solo on the main...

playing around in bgs is a mix of boxed or solo... raid finder for newer teams is gear and a mix sometimes of more geared toons too carry the lower item level ones and need to trade loot, or to just show off in raid finder lol.

army of xmuters and jc'ers as well, used for gold making purposes, also use boxed toons to mount farm as well..

So a bit of this and that boxed and solo, never goes stale imo