Biggest problem with rimfires is the transfer bar, there have been lots of them returned to the factory for repair due to light strikes/no fires. Other than that, everything else is the same, although they're ejectors at this time, no issues with ejecting tho.
Cost wise, an accessory 22Lr rimfire barrel will cost as much if not more than a complete rifle after shipping both ways and fitting, while the 22mag, 17M2 and 17hmr are about $130-$140 for a rlfle and acc barrels over $100 with shipping.
Tim