We have a few thousand rounds through ours and it has been fine for the most part. We have had no problems with accuracy. There is the occasional misfed bullet, but otherwise it functions fine. There are two big drawbacks to these however. Spare magazines are hugely expensive (for all brands of .22 conversions) and stripping down the conversion unit for cleaning can be tricky.
My wife uses the conversion unit to warmup with before shooting her Classic Stainless in .45. While the .22 recoil is nothing compared to the .45, she can work on trigger control drills since the trigger is the same. Generally speaking, this has helped with the accuracy of her shooting.
Another nice thing about the .22 conversions is that the converted gun will fit into the same holsters you have for the .45. So if you are hoping to use the gun as a trail gun or something akin to that, you don't have to buy another holster.