I won't say that it's better than Fallout 3, but it does have some things about it that give it an edge. Perhaps the significant lack of Supermutant Overlords helps (I hate those things!).

I just need your love!
First off, it's harder. Combat is roughly the same, though it is almost easier to fight without V.A.T.S. I like that, as I had a hard time doing so in 3, except when sniping. The enemies are also very similar, but the addition of various levels of Deathclaws and Nightkin (so badass) give it a nice twist. Also, one might encounter these enemies at any point in the game. No need to wait for level 12 to run into some Deathclaws if you're brave enough to venture into the quarry.
It's also more difficult because there's no real safe haven. In Fallout 3, you could get house or apartment to store gear, there was an abundance of ammo, bottle caps, and aid, and levels came more quickly with less difficult quests still being worth boat loads of XP.
Not so in New Vegas, at least for me. But I like to take things slow. I'm also finding that the reloading and trying speech checks over and over doesn't work. If you only meet 43/50 for the check, you won't get it. It's a challenge and sometimes you have to wait to do things for a while.
The weapons are better though, and the ability to modify them (with enough repair/science skill of course) definitely adds a new dimension to the game. Also, the karma levels are specific to groups of people. I have a few towns and factions that like me and two that vilify me. They might have gotten me if not for my sniper and Eye-Bot followers.
The differences are really what make the game but it's always heartening to see some similarities.
Fallout 3

New Vegas

It's the little things that matter.