So I installed this Ubuntu desktop edition, got a feel of it, but I'm think is it better to have a netbook edition on my laptop? Does the netbook edition use less space than the desktop edition?
Less space? No. What's the point in using less space? It only takes up a few gigs anyway. Once you have all the other files, it's irrelevant on a 120GB HDD.
The netbook edition is basically good for small screens. That's it. At one point in time it was lighter, but it's as horribly bloated as normal Ubuntu, now.