I've had the G43 for two range trips now and I don't see much reason for the G42 anymore.
The G43 seems more reliable. I encountered the premature lock back problem with certain ammo in the G42, though I think by sticking to ammo with better geometry, this can be avoided. The G43 has been 100% through it's first 650 rounds, and I'll be carrying it once I get a smooth faced trigger on it. I could not get the G43 to malfunction, though I tried mightily.
The G42 is a little lighter and has less recoil, but not much on either. In fact, I've been surprised how little recoil the G43 does have as a 9mm in this size - it's very manageable and comfortable to shoot. I did blister my trigger finger the first time out with 400 rounds, but a smooth trigger shoe will fix that.
For personal accuracy, I still have the most trouble shooting the G42 well among all my Glocks. The G43 hit the target much better from the start, though it will take a lot of practice before it works as well as the G26. Given the better round and cheaper ammo you get with 9mm, The 43 is it for me.