Mega Man X5I've always heard the series took a sharp drop downhill after X4, but I could never be sure if it were really true or not. So I've gotta say...
...Yup it's true, X5 is terrible. Stage design isn't just poor, a lot of it borrows ideas from past games in worse ways, particularly the final stages, and there's less variety. I guess they became creatively bankrupt after 4. This isn't the end of it though. The game is also timed in a way that decreases each time a stage is played, whether completed or not. This serves to discourage the usual exploration until all eight regular levels are finished. What's more, the lower this counter gets, the "higher level" the bosses become, gaining more health the longer it takes to beat stages. On top of all this, they learned nothing from complaints about Nintendo and added an annoying helper character who stops the action to point out mostly obvious stuff every couple of screens. Seriously, one of the help messages is literally "You should proceed by stepping on the platforms."
To say one positive thing, the idea of scaling bosses based on the player's completion kinda makes some sense for these games and the way upgrades and weaknesses work, which can make it easier to start things out before all that stuff is obtained and help prevent becoming too powerful. But X5 poorly implements it.
Did you play as both X and Zero? X4 was literally designed with Zero's close combat in mind so playing as X is pretty much an easy mode. Zero story is also the true story in the canon as well since X5 will even refer to events that are only shown in Zero's story.
Yeah, I went back to check out Zero to see if anything were different. Maybe it's because I was familiar with the game at that point but I actually found Zero to be general easier. There are a few trouble spots and bosses where not being able to shoot is a real hindrance, but the saber is so powerful that it wreaks everything it can reach. I zipped through the eight main stages, but seeing nothing was really different I stopped short of the final.