X3 is decent but it is undeniably the most forgettable for veterans, but for beginners and people who don't know the game well some of the things are a guide dang it and if you're reckless in the beginning stages you'll die in 3 hits. I think it shares similar problems with X6 in the way that they pack in way too many gimmicks though instead of being annoying most of it is not useful and you can go through the game just fine without them.
I mean look at all the collectibles, armor, heart tanks, subtanks, ride armors, 1 of the chips or the golden armor, and the Z saber, honestly the only thing that's useful in this group is the body armor, air dash, heart tanks, sub tanks, the Z saber if you want to cheese Sigma and maybe the buster upgrade if you want a little extra power, emphasis on a little.
Boss AI, as everyone pointed out, is hilarious, if I wasn't so awful at Megaman games I could probably beat them like no one's business. I mean even the mid bosses and Sigma aren't any different but Sigma is the hardest fight in any of the X series since his first form fires so much stuff at you and his second is so huge and still fires so much stuff at you.
What boggles me is how people figure out everything without a guide, especially getting the Z-Saber.
It's a coincidence that this topic is here now since one of my subscriptions on Youtube just finished X3 and the commentary grouped pretty much sited the same reasons of why they didn't like X3.
WAYYY.......TOO.....MANY.....GATES.
That is all.
I also agree with that.