Just bought a used AF540FGZ II for my K-1. I'm hoping it's more consistent in PTTL than my Metz 58 AF-2s. I was shooting an event last Saturday in an (admittedly) very dark hall - AF was hunting all over the place. The Metz AF assist beam doesn't operate on K-1 and the K-1's own in cmaera beam doesn't operate half as often as it should in low light. Pentax definitely need to sort the K-1 firmware out for this issue.
Not Pentax, but I just bought an LA-EA4 af adapter off ebay with a cheeky snipe at the last second. Also a Minolta 35-70mm f4 af lens to use with it, along with my Minolta 28-135mm, which was free except for cleaning. Also recently got a Minolta 300mm f4, Domiplan 50mm f2.8 (along with a working Practica L2; a fiver for camera and lens. I've just put a film in the camera), and a Cimko 24mm f2.8 bought by accident (unexpectedly, it's sharper in the corners than my Sigma Super-wide II 24mm).
Don't ask why, but I've just bought a black Asahi Pentax H2 with an Auto Takumar 55mm f2 and an Auto Takumar 35mm 3.5. They won't get much use (if any - the shutters are known for problems) but it's such a beautiful little outfit I just fell in love with it