> I've heard the [K|M]28/3.5 is sharper than the 2.8? The K 28/3.5 (and this is also true of the K 35/3.5) is one of the best Pentax wide-angles (IMHO). A little slow, of course, but excellent sharpness, contrast and distortion, and available for generally a low price (although this does vary a bit).
I am not personally familiar with the M 28/3.5 (which is different from the K 28/3.5). Although you refer to "the 2.8", there are several versions of Pentax 28/2.8's, and I understand they do vary quite a bit in quality. My personal 28mm favorites are the K 28/2, the K 28/3.5, the A 28/2, and the VS1 28/1.9. I guess that the FA 28/2.8 might be a good one to look for, too... Fred