On the whole, we like nuget and have moved over to it for all our newest projects.
There is a pretty nasty bug/flaw with it though that caught us out. If you have multiple solutions in the same folder then one solution will stomp all over the other one and vice versa and mess with the packages. Nuget obviously expects solutions to be in their own folders.
This caught us out really badly at first, as our TFS system is set up with the solution files for each of our main applications all to be in the root of the TFS store. Probably not a best practice, but that's how we've done it for the last 7 years.
Moving the solutions into a 'solutions > solutionname' folder has solved this problem, but it was a hassle to begin with.
The other thing we wish was better would be a way to right click and refresh a nuget reference. Right now it's 'install' or 'uninstall' only (or 'update' if there's a newer version). We keep running in to nuget references that mess up and we have to remove and re-add them. Not a huge deal, but would be nice to right click and say 'refresh all nuget packages'.
Other than that, we like it.