I would prefer a dedicated .22LR upper, but I didn't know anything about them when I bought the conversion. However, I am adverse to spending $400-500 for a .22 upper.
I had the same reservations, but once I realized it would probably be the most used gun I own, it was easy. First time I took my Spike's to the range I put 1100rds of Federal bulk plus assorted CCI and wins. Saved about $400 in ammo costs on one range trip while shooting the same platform. Don't regret it at all.