I have one. Paid about $400 for it used, but in near NIB shape about 2 years ago. Put a Williams rear peep on it and you couldn't buy it from me for 2x what I paid. It's my if I could only have one .22. That thing is scary accurate.
Unfortunately, I tried to get some spare parts from T/C some time ago and they have none, nor could they point me to any. Mags are like hens teeth too.
Also, beware of the extractor chipping the chamber. Some of the earlier models had this issue, it requires careful reshaping of the extractor to prevent it contacting the chamber in the extractor groove. I did it with some 400-600 grit sandpaper, a piece of glass and a lot of test-fitting. If the chamber does chip, S&W won't fix the rifle. They just replace it with an M&P15-22. Not an even trade to my mind.