As a Pentaxian I of course have winders for my LX cameras. They feature power rewind, which is nice. I like the winder on my MXs, they add just enough heft, and make sequences, regardless of the speed, easier. However, the MX winder's Achilles heel, IMO, is the tiny "cap" for the 4 AA cells. Too easy to drop, and at some point the tiny screw will strip out. Not a good idea for Pentax's foray into the Pro marked. The MX system included a 5fps motor drive, a bulk film back, interchangeable VF screens, etc.
Much nicer is the battery tray for the ME Super. Why didn't Pentax use such a tray on the MX?
Nikon is becoming my secondary system. I have the F, the f2 with winder, a F3, and the F4 with winder. The F4 is a real horse, heavy enough to make a good weapon. The wineder is nicely integrated into the camera.
BTW, if any fellow LX owners can suggest a good person for a CLA please let me know. Eric Hendrickson, the Pentax "go to" man no longer works on the LX, citing the unavailability of parts.