Well, see, this is the trick with litestep, because it is so modular and you can really do whatever you want to, most of the questions can go either way.

But here is my list of things:
#1) Way more stable, especially under win9x
#2) Uses less memory (for me, but I'm minimalist)
#3) Quicker to use, with the quick user defined popups, shortcuts, hotkeys, etc
and of course, #4) You do whatever you want, which is cool

Downsides..
Can be sketchy with buggy modules
Can take awhile to get exactly what you want with a theme
People don't read the documentation and freak out

All that said, give it a go. If you install a shell manager theres really nothing that can go seriously wrong.