Been using the H4D-40 (35-90 and 150) for a little over a year, here's the pros and cons. Pros-Files are great, lenses are very sharp, leaf shutter. Cons-Weight, focus speed. I had a chance to try the Pentax 645D and was very impressed with the weight and focus speed. I can live without the leaf shutter, I just need a file with enough resolution to go to a 40 or 50 in print. The question is, have any of you compared the two, used them both, have any input on image quality? The Pentax lenses I'd use would likely be the new 90 and 55. As to work, I do family portraits exclusively, on the beach and in the studio, thanks.