#2: The Pentax 645 is very easy to use, and the lenses are sharp. You can put it on a tripod for either landscape or portrait.
Originally Posted by puketronic
#3: I've never had a problem with Pentax bokeh. Bokeh is rather subjective, anyways. I have a few pictures in the gallery that I shot wide open with a 75mm f/2.8.
#4: I have a Pentax 6x7. Yes, it's a heavy camera, but a good ball head works just fine with it. I have done a few portraits with mine, but my personal preference for portraits is a view camera. If you don't have a totally solid tripod and head, then be sure to lock the mirror up.