IMHO you are comparing apples to oranges really. The P22 is a sub-compact sized 22lr while the MP 22LR is a full size service pistol in 22. I own the P22 and have never had an issue with it and it shoots all types of LR ammo (bulk Fed, AME, Remington etc). I know the internet is full of horror stories but my experience tells me that there are always tonnes of stories about EVERY gun out there. It seems somebody somewhere always knows someone who once heard that X gun will melt if exposed to air. C'est la vie! My advice is do your own research and try to get trigger time on whatever it is you are interested in so you can see what works for you.
In a nutshell, if your looking for a good solid beginners 22lr either would work. If you want a "service pistol trainer" I would go MP22 handsdown. If you are Teaching the kids, elderly Grannie or small handed individual (husband or wife) to shoot then the P22 is a great place to start. Even if you are a large burly man with hams for hands the P22 is a great gun, you just need to finesse the grip a bit but the MP22 would probably fit better.
Also, consider the Ruger Mk 2, 3's. This forum will give lots of reasons why they are awesome pistols to have, particularily as a "first gun".
Get what ever floats your boat and meets you needs!
Have fun.
In a nutshell, if your looking for a good solid beginners 22lr either would work. If you want a "service pistol trainer" I would go MP22 handsdown. If you are Teaching the kids, elderly Grannie or small handed individual (husband or wife) to shoot then the P22 is a great place to start. Even if you are a large burly man with hams for hands the P22 is a great gun, you just need to finesse the grip a bit but the MP22 would probably fit better.
Also, consider the Ruger Mk 2, 3's. This forum will give lots of reasons why they are awesome pistols to have, particularily as a "first gun".
Get what ever floats your boat and meets you needs!
Have fun.