Shooting left of center is nothing new for the Glock design and certainly not exclusive to the Gen5. Some pistols seem to do it and some don't but I will say that we are seeing it less with the 17M than we have with previous generations. A significant number of pistols that shoot left mysteriously stop if someone else shoots the pitsol. When it does turn out to be the pistol if it doesn't require a significant adjustment of the rear sight I've never considered it to be a big deal.
The slides coming off story seems to have gained a life of its own. The issue was not with the Gen5 Glocks, it was with the very early 17M pistols and was quickly and easily remedied with a stronger slide lock spring.
I know about the 17M debatable. Apparently the Gen5 17 needs a different slide takedown spring. I'm just stating what was said to me. And it didn't come from some fudd.