I'd strongly suggest you stay with Snow Leopard. That's what I have my entire network centered on, several recent Macs (just before they were shipping with Lion) and the rest of my Apple eco-system.
The only exception, is my 2011 MBA with Lion from Apple, I bought it for the sole purpose of testing Lion on a new Mac to see what it was like when shipped on an appropriately equipped MacBook.
I'm not a hater, or one that bashes Apple, but I do speak my truth as experienced personally. No guessing, no speculation, no operating off others reports.
For me, Lion is simply not that great, too slow and cumbersome (I have maximum ram too). Too many consumer oriented changes and eye candy. Certainly not even close to use for mission critical engineering, scientific, research and development work like I do.
Having all my others (15 & 17" 2010 MBP's, Mac Pro, etc) centered on my highly optimized 10.6.8. I'm not about to disturb a well sorted out network, and series of Macs.
Fast forward to today. It appears that Apple is working more aggressively than ever to put Lion out to pasture, getting it behind them. Replacing it with Mountain Lion which I'm guessing must be a better more reliable OS.
I'm going to continue to take a wait and see approach, and with luck perhaps Mountain Lion will be a good, stable, reliable, secure OS. One that's worth upgrading to for business and personal. Then I will migrate just one MBP and evaluate it before undertaking the big project of converting my entire network, NAS and all computers.