I've done a little bit of servicing of the Rollei 35SE, Minox 35EL and Olympus XA, and for what it's worth, I thought:
Rollei looks very nicely made. Mine already had a brass gear installed in the film wind mechanism. Want to be careful not to lose the lens trim ring which is only lightly cemented into place, and said cement deteriorates over time.
Minox was one of my first repair attempts, but even so I was able to fix an electronic shutter which wasn't opening correctly. Never had further issues. At first I was annoyed by the apparent lack of any manual exposure control until I realized that the ISO dial can be effectively used as such.
Olympus XA is a thing of wonder: First of all, rather than design a complex mechanism to retract and extend the lens, they reworked the optics such that the rear lens element is enormous and sits much closer than normal to the film. At least superficially, it appears similar to what Fujifilm does with their X100-series cameras, and Sony with the RX1. It also seems to be the easiest to service of the bunch. Does it make the others appear quaint by comparison? Oh, just a little...