try Freespace, is the best space "sim" ever, at leat in balance and gameplay. Because I-war it´s more realistic, but it´s definitively unbalanced in comparison.

I'll second pretty much everything YaTEdiGo said.
I don't remember WC4 being that much harder than 3 when they just came out. But it sure is now, comparing the default 'Ace' setting, though the setting isn't the point, I'll get to that.

Missiles and collision damage make the game pure frustration. It's not the rest of the AI. It seems your opponents use the wingman system better than in WC3, which means picking them off, one by one, harder. That's good. But the number of missiles they fire and the damage those do, make surviving the missions in something like a Hellcat(and most of what you fly) a crapshoot at best and a long-shot most of the time. A single missile can kill you. Maybe combined with a minor reduction to your shields, but I'm quite sure I've been scratch free one second, and space dust the next, with just one missile hit. You can do the same to the enemy, like YaTEdiGo says, but the constant dying takes the fun out of the game. And the lower difficulty settings affect stuff that doesn't need to become easier. Unavoidable collisions still occur and kill you, missiles seem to do the same damage.
I can't imagine a game this slick and beautiful (it still is as far as I'm concerned), developed by Chris Roberts, didn't get proper gameplay testing, but it seems that way.

Come to think of it, one of the main reasons I got this game from GoG was because I remembered the Dragon and wanted to fly it again. Now I now why.

[edit] just did a little test; entered a dogfight in Rookie setting, which is silly easy (auto aim, enemies are idiots). Switched to veteran in de the middle of it and the one remaining Banshee-Ace(and they all seem to be) instantly launched missiles; 5 of them within 4 seconds to be exact. Each of which is potential instant death. Dodged them all, this time. I do still wonder if the original CD version of the game was this unbalanced. FMV is real pretty now, though.