the internet is full of miss information, but the glock problems are (were) real. At the beginning the gen 4 had problems with the recoil springs, the new ones were modified a couple times until they figured one that worked, that one is 0-4-2.
After that, people started complaining of BTF (brass to the face) and erratic ejection patterns (ejector 336), so glock replaced their ejectors with another one that I cannot remember the number but I think is 2286. I have seen many glocks, and they all have erratic ejections, some more than others, some, have a weak ejection, some eject to the left every once in a while and so on. So there are little problems with the glock that can be fixed by replacing a couple parts.
I bought a glock from someone here in very good condition and it ejects fine. I replaced all the springs and ejector and the ejection pattern did not change at all. Shooting 124, it ejects at 5 o'clock, 3 feet away, not bad.
One thing I noticed with the glock is that it is very sensitive to 'limp wristing', and found that the glock ejection pattern will change if my grip, arms, stance are not properly locked. This mostly happens is I am shooting from a bench.
I like the glock for what it is, I am lucky it fits me very well. It is far from perfect, the ejection button even on the gen 4 is a torture to use and the slide release it is not the best of the best. I love it's simplicity and that is can be taken apart with one single tool, parts are everywhere, so that is hard to beat. I shoot the Glock well too, but I shoot the hk a lot better, specially after I shot the Glock for a while.
I think you should give them a try! they are fun to shoot!
Good luck!