I now own 6 of them and still do 80% of my personal training with my original G44. I always shoot about 50-rds of 9mm to maintain my familiarity of the recoil impulse of the 9mm. I also shoot lots of IDPA and IPSC matches with my G17.
The G44s (all 6 of them) have been nearly 100% reliable using Aguila Super Extra 22LR and Federal Champion. It is also 100% reliable with cheap ammo like Thunderbolt, but I soon discovered, due to its soft lead, it fouled the rifling in less than 50 rounds. I could not even group after the barrel is fouled. My gunsmith told me he had to use a torch in order to get the lead off the rifling. No such problem with Federal Champion. The only downside is when teaching newbies with G44, I have to also bring either G17 or G19 for them to dry fire. It is a inherent problem training with a rimfire gun.