My 2cents:
For me, SL ist THE working environment. I use my computer mainly for work. And SL helps me do it just the way I need. I do programming, designing, administration, scientific stuff, ... Everything is pretty perfect.
I bought a new Computer when Lion came out and I boucht one when ML came. Because I need to test my software on different systems. And buying a new computer is just the most hassle-free way to do that. They sit somewhere on my desk and are used maybe two times a month. They are testing machines. Working with them? Hell no!
There are some things though, which I would like to have in SL: Vertical window resize, the newest Safari without the upload-bug and maybe the new less-rounded buttons. But thats pretty much it. App store is ok too. Helps me find out what my competitors are doing.
But it's already there in SL, so why bother.
We'll see what 10.9 will be. SL had so many great features for me as a programmer. Let's hope 10.9 will be more like that.