I agree about the T2i, it feels cheap. The copy I had didn't have the issues you mentioned, but it isn't a camera that I'd want to do much serious shooting with. Of course that is just based on how I shoot.
Nikon's entry level DSLRs feel better made than the T2i, but that has been the case since the Rebel line of cameras was first introduced.
As for the 60D, if it feels as nice as the 50D, which is the only Canon I've spent much time with other than the T2i, then the grip is really nice. Honestly I find the feel of the grip on those cameras fits my hands a little bit better than the D300, which I already really like.
The viewfinder is a biggy, when you look into the T2i or other entry level models it is like looking through a tunnel. Heck, I want to upgrade to full frame simply for the bigger finder (the crop sensor ones cause eye strain). I can shoot with my F90X (film camera) all day and have no eye strain, but with a crop body, it can be an issue. The bigger and brighter the better!