I have a MKIII 22/45 and I can attest it is a great gun. Not my personal favorite to shoot, that acclaim goes to my 12 gauge but my girlfriend loves it and it has been very reliable. Without an aftermarket magazine loader of some type the mags are difficult to load, luckily there are a few very neat options available for that. Also, yes it is a pain in the ass to take apart. Plenty of you tube videos on the subject. Mainly a pain because of the pin you have to take out of the rear that can be hard to get out, and the order in which it goes back together can be hard to remember if you do not do it often. The trigger... meh...well when you go from shooting something with a good trigger directly to the mkIII it feels like a toy gun or something but...for the price doubt you can get a nicer .22

I do kind of wish I got the regular mkIII instead with the luger type grip, rather than the 22/45 which is meant to mimic a 1911 with the same grip angle and controls.... I hear it is better for more natural aiming. And it is all metal wheras the 22/45 has a composite grip assembly.

walther P22 is a great .22lr.  mines feeds and shoots everything!  I was gonna get a mp22 but never could find one for a good price locally.