I didn't play NV on 360 much.
I loved F3 and covered almost the entire map. I don't know how many hours I sunk into it, but a lot, especially since the loads times are awful. After beating the game, I purposely reloaded an old save and and took the super mutant NPC with me to clear out endless buildings and side quests. I think I cleared out about 80-90% of the entire map.
Maybe it was burn out, but I bailed ship maybe 5-6 hours in roaming the land in NV. I know some reasons I bailed was it was such a boring brown setting. Maybe I didn't get to the good parts, but I just saw brown everywhere. Even the default HUD is orange or tan. I changed it.
You find mutant sand bugs, random bandits, and there was major animation/glitching going on which I never saw in F3. NPCs glitching through walls and was stuck in the ceiling!
Of course I read they patched the game good. But by that time my interest was lost. Maybe if it was patched good from day one I would have stuck around longer to see better parts of the game.