I know this is an old question, but as I have the exact same netbook and the exact same problem, I feel like I should answer anyway.
I really loved the ubuntu netbook remix, and I was very sad when I had to upgrade. The new Unity just didn't feel right, as you said it felt slow, and also big and clumsy. I really liked the layout and workflow of the netbook remix.
I was already familiar with lubuntu, but I don't quite think it's ready for everyday use. Yes it's amazingly small and fast, but it still seems to lag behind the more performance hungry competitors in terms of usability. I often have to use the command line in order to do stuff that should be really simple.
Enough bad things said about other desktop managers. What I ended up choosing, was xfce (xubuntu). I know someone else mentioned it, but I think it deserves more credit. I was really skeptical at first, because last i tried it, it had the same issues as lxde (fast but not very user friendly), but having read a really positive review on deoimedo, I felt like I should give it a new try.
It was everything I could have hoped for, and more. The customization tools are just awesome. I was able to mold it into something extremely similar to the netbook remix. That is, the panels are shrinkable, movable and custimizable in every way. Text on the taskbar buttons can be disabled to save space like in the netbook remix.
I also got a lot of stuff that I missed on the netbook remix, like several work spaces. The only thing that's missing, is the menu that used to be where the desktop is, and the window border doesn't integrate with the taskbar like on the old unity.
The performance and snappiness also felt better than on the netbook remix. And in terms of usability, everything is just great, I still haven't had to use the command line for anything that should be simple.
So in my opinion, xubuntu is both faster, and has better usability than the netbook remix.