We have an Olympus Stylus (which appears now to be bricked), the American version of the original mju, and I now have a mu ii. I also briefly had a mju zoom that someone advertised as a mju II. I concur with
@Retune's suggestion, mju II > mju > mju zoom.
One advantage of the original mju that I don't think has been noted is that the shape is better (I think), slightly larger and easier to open the clamshell. Also, IIRC, the original mju doesn't default to "flash auto". With the mju II you have to switch off the flash every time you turn it on, which could be multiple times on an outing (not that flash fires every time, but that it decides when to fire on its own, and it's very annoying as it changes the shot a lot).
The mju II f/2.8 lens IMHO is much better than the original f/3.5 lens. I think the zooms are even slower, and from what I've seen, results not so good.
Very easy to load. Very pocketable. But for some reason it takes me months (actually years, it appears, last finished roll was finished in October 2018) to finish a film, as I never take the cameras out with me!
They're also completely automated. Point, shoot, whirr (or, at the end of the roll, Whirrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr).