Originally posted by wlank If it works for you, that is great. The way I use M42 lenses is entirely different than the way you do. You may have noticed in my Sig. that I'm the "Proud Owner" of a Spotmatic and that I have several M42 lenses. I use that camera rather regularly and I don't intend to permanently mount an adapter on any of those lenses. I notice that you do NOT mention an M42 body in your gear list.
My gear list says "Some other M42 bodies". Left unnamed are a Chinon-Argus CR-3E, 3 Prakticas, a Fujica ST-701, and some others. Of M42s, the advanced Argus gets the most use, then the prismless Praktica FX3 with its top viewfinder. I also don't name the non-M42's and the rest of my camera pile (around 40). I think my lens count is ~175, of which 7 are M39, ~60 are M42, and ~35 are PK of some sort. About 20 total are Pentax. That's just too much detail for my gear list.
By "permanently mount", I don't mean SuperGlue. I mean, screw it on snugly (using a rear lens cap as a grip) and leave it on until it's expedient to screw it off, rather than dicking around with the screwmount whenever I change lenses. Most of my shooting is with the K20D, then the ZX-M, so the dozen or so M42 lenses I use most get adapters (until it's time for a different lens). On a long drive I typically pack 4 SLRs, 25-30 lenses, and yet more cameras and stuff, in flux. The only thing permanent is change.
"If all you have is a hammer, every problem looks like a nail." My kit is more like that 57-pound got-it-all Swiss Army Knife, which includes an Official Pentax Adapter, and flanged adapters, and Bowers adapters. Different tools, different nails.