It's waaay better than most other games out there.
even in spite of it's rather linear path, loading screen havens (looking at freeside and the strip here), nerf of fat boy (why bother putting it in at all when there's like 5 mini-nukes in the entire game?), weak energy weapons (not ineffective but you'l notice when you use a laser rifle how lame it is without critical hits) oh and did i forget to mention the horde of bugs? yes there's lots of those and i'm not talking about the ants although ironically the bugs seem to affect the bugs most

.
The way i'd improve the game is simple, make fat boy weapon actually cool again, make energy ammo more common, make energy weapons more powerful but harder to find.
As for the loading screens in the strip i would try and implement a rather simple system whereby you can if you wish reduce the numbers of npc's to spawn in an area (you know those random ncr soldiers who never say anything to you other than nuclear winters), increase the size of the area loaded for the strip (seriously 3 barriers?)
Throw in larger numbers of gangers and thugs to roam freeside, weak but lots, to remove the grindfest that is freeside.
rip out all the errand quests for the followers/kings/crimson caravan/atomic wrangler/camp McCarran, such a waste of time. replace them with either interesting dialogue options, or cooler gunfights. have a more interesting play-off of rival gangs and groups there.
i mean what a missed opportunity for freeside to be cool.
Oh and ditto for the strip, although those ones weren't so much bad as too few. plus all of the shortcuts removed for weapons after they take your gear is such a nuisance.
A massive nerf to experience gained from completing quests, again strip out the errand quests, unless they either have cool dialogue or serve a purpose to the main story.
Give the player an option at the start, you know like where it shows the hardcoe option whereby they can choose to have quests give less experience for the gunslingers, or more experience for the people who want to complete the game without killing anyone (how or why those people bother are beyond my comprehension).
throw in some more random notes and stories in the wasteland too, i liked those they add healthy immersion.
oh and i'd make the wild wasteland perk actually cool.
idk how about shoot-outs between a rogue gang of securitrons and grannies armed with shotguns. with random dialogue for lolz.
oh and finally i'd throw in more computers to hack, and robots to fight. i think those where lacking a bit in this one. idk how about a courier service run by robots delivering parcels?
don't get me wrong i love the game, i think it's really well done. it was released too early is all.