Constructed to the same physical dimensions as the G19, the G44 only differs in weight due mainly to differences in slide construction. The .22 LR slide is lighter, as the round has less power available to cycle it. Where this comes in handy for training is that the G44 will fit all G19 holsters, so you can practice all your shooting from concealment drills with the more economical .22 LR. You'll still need to practice all the fundamentals and make good hits, it'll just cost less. Now, yes, MSRP is $430, which should translate to something lower off-the-shelf, and there's a lot of 9 mm ammo you can buy for that kinda money, true. However, in the long run it totally pays for itself, over time, as you practice more and more confidently.
And lastly? It’s just plain fun. There is a lot to be said for a gun you can take out and plink with, not doing anything necessarily serious. It also makes a great introduction to semi-automatics, as it has the same look and feel of its centerfire sibling, without all the kick. For a new shooter, it’s a great idea.