I have the PT-22.
I feed it CCI stingers and mini-mags and it runs quite well. The trigger is a long double action pull, but it is very smooth and not really that heavy. I've probably had around 1000 rounds through it by now.
It is definately a fun plinker, and makes a so-so absolute last resort type gun. Reliability is as good as a .22 can get with good ammo, and it can be fired quickly and relatively accurately. I don't generally fire more than 100 through it before cleaning though, as crud tends to build up and affect feeding. A good wipe down at the range with a rag and it's running fine again. I've actually had up to 150 through it before it started to hiccup a little, like I said though, reliability is fine with good ammo, and a clean gun.
Given the choice, I'd go for the beretta version of this gun, it may be a little more solid, and if anything the SA/DA trigger of the 21A is an advantage. The Beretta can be shot very quickly.
If this is for defense, it makes a decent backup gun. If this is for a primary carry, your money would be better spent on a .38 snub. Rossi makes a fine one and it can be had for just a tiny bit more new.