I've just finished playing my second character (female, pro-Caesar). My thoughts:
What I see here, despite Avellone not being the main writer and the senior designer instead, is a port of TSL minus its directly Star Wars-related aspects over to Bethesda's engine and given the world of Fallout. Does it work? Minus the bugs associated with the engine that vary from computer to computer...perfectly.
I've honestly never found an RPG before Fallout New Vegas that combines interactivity and effective story so well. To a degree, this world is truly dynamic: your actions have significant consequences that play out, resulting in choices being both created and destroyed. It does not need flashy graphics because the content itself immerses the player.
The game mechanics have noticeably improved. Gun damage is more appropriate: a .50 cal shot to the head equals death, with the plot-induced exception of Darth Nihilus...I mean Legate Lanius.
Melee is reasonably powerful, but not excessively. Unarmed also has practical uses. The skills and perks work very well and do not result in god-characters (your character will still be godly due to the fact that he/she/it is a main character but not absolutely so). Whoever thought of the challenges system deserves an award, since it helps reduce the need to grind quests.
The companion system is noticeably better but still needs work. Veronica has serious pathing issues. A larger variety of radio music would be nice, but I'm betting there are plenty of mods out already that handle that. VATS is still VATS and in my opinion overhyped for what it is.
Anyway, I rate this game a 9/10, overlooking the various bugs because I wasn't surprised they'd be there. In fact, I'm rather irritated by some professional reviews that rated New Vegas so poorly purely because of said bugs, many of which were already present in Fallout 3 and were reduced in this game. I believe that amongst today's RPGs, most of which emphasize cutscenes and graphics over content, this actually delivers a truly solid gaming experience.