OK I finished this last week, the ending was so uninspiring I'd almost forgotten it already. Epic isn't how I'd describe this game, there were some good parts but they seemed more early game (pre-Vegas 'join a faction' main quest). I followed the Wild Cards/Yes Man branch while doing as much of NCR/Slavers stuff without alienating any faction totally, the setup of main quest (find allies)->'cut-scene' end game was almost Dragon Age/Biowar-ish.
Actual end-game was so easy I was sure it couldn't be the end game, and I was not even very well equipped. Combat Armor + unique grenade rifle I obtained around level 15 from Boomers + semi-auto rifle from Vault Radio-active, shoot a couple grenades at mob of charging Centurions switch to rifle to finish them off, repeat. My explosive skill was only 40-50. The only difficulty I had was when I brought along stupid cyber dog I'd just found (E-DE was out of action getting repaired) who charged into Centurions every time to get killed. Also I was playing on Arwen's hard-core realism with shock/crippling/bleeding wounds and no stim-packs (can only use out of combat)
Noticed a few C&C oversights along the way, eg in NCR HQ investigate the traitor, Slavers' spymaster trusted and already gave me the name of his agent. In NCR base I can go up to him and have the choice "I know who you are" which then forces you to go along with his plot, OR you have to pretend you don't know anything, look for clues and eventually spy on him in control tower. Like designers didn't consider any PC double agent path.
Also disappointed that there wasn't double-crossing option more generally. You can help both the NCR or Slavers one bit at a time, up to as far as it allows you... eventually game's magic invisible spies inform factions and they give you an ultimatum. Since my decision was to go Independent I thought I was being clever selectively 'helping'/sabotaging the two main factions about equally so they would weaken each other... eg repair Slavers' howitzer, destroy NCR mono-rail and free Slaver captive to hurt NCR but give Slaver secret plans to NCR, help with their morale/supplies problems. I got Boomers to promise to help me and thought Brotherhood were on my side... none of this made any difference I could see to end battle. Boomers, Brotherhood, Casino factions nowhere to be seen. Just me, rifle, Cass and a handful of robots methodically clearing room-fuls of generic Legion/NCR troopers. All the two major faction stuff I did is just extra XP side quests no game impact
Compare with Dragon Age where who you help/choices made during main quest segments (eg Tower paladins/wizards, elf/werewolf) determines unit availability/difficulty of main battle. Even if it is mainly cosmetic it's nice to have game recognition of choices
Are the other endings/routes better designed/more rewarding?