767 is very similar to the 757.  As in nearly identical.  If you like the 757 you'll like the 767.  It has the complete cabin, and sun shades, as well as a slightly different overhead.  I think it is a better airplane.

The only bugs I see are the occasional engine sound when engine is off, and the porpoising during cruise.  The latter looks like it is on its way to a non-issue now.  So, what it comes down to is whether you want a 767 or not.  The 767 can make long transatlantic flights, and now, with the -200 out, transpacific flights, as well.  If someone put a gun to my head and made me choose I'd be going with the 767 until I thought about McPhat 757 paint jobs on the way... it would be hard.