Here is a shootout test by a DPR Pentax user, full size comparison shots and crops are posted:-
http://forums.dpreview.com/forums/read.asp?forum=1036&message=34097456
(Full Size Samples - Warning: Very Large Files to Download)
http://forums.dpreview.com/forums/read.asp?forum=1036&message=34098453
(Crops)
Well, the differences are obvious and I agree with the observations of and conclusions as drawn up by the poster. Of course, you can ignore all those and just view, inspect and judge yourself, first.
Happy (or maybe unhappy anyway) measurbating! ;-x