Just completed Old World Blues, and I'd have to say that I'm pretty disappointed. Now with these games, it all depends on your exploration that gets the most out of them, but when you're being attacked by enemies who have 100% accuracy and are a bitch to kill, it can get fairly unproductive to stray from the path as one would usually do.
The lack of ammunition was annoying too, sure they give you a ton of different guns and crap, but I'm the kind of person who prefers firearms and doesn't use energy weapons what so ever; I was pretty lost with them after my ammunition ran out.
If you're a Fallout: New Vegas completest, you might as well go for the DLC and download it, but if you're a casual gamer I'd recommend skipping this DLC because it left me feeling like I had wasted $10.