For me, and I stress this is MY opinion and MY experience, having spent extended time getting to know the ins and outs of Lion a bit more, Snow Leopard is a far superior user experience on my Mac than Lion.
My initial reaction was WAY off, massively so in fact.
I find when Lion is first booted, it runs brilliantly. Within the hour, it begins acting up. Animations going to/from full screen mode can stutter, as do the animations opening/closing folders on Launchpad.
The system can feel, in general, sluggish (especially scrolling on Safari) after waking from sleep, and the RAM management is quite frankly shocking. Yes, I know the old argument that inactive is the same as free continues, but in my experience RAM must be used and allocated then freed up by quitting the application using it, to become inactive. Lion, again, within the hour allocates any free RAM to inactive and that for me is what bogs my system down.
I used iFreeMem as a trial, and when optimising RAM and returning inactive to free, there was a marked improvement in performance, but Lion should not be turning free memory into inactive memory when nothing has used the RAM and been quit in the first place.
I'm going to relegate Lion to the external partition and bring Snow Leopard "home" over the weekend and put it back on the internal. Even running Snow Leopard from the external WD drive, it's just a slicker, quicker user experience on my Mac (note MY Mac, everything above is MY experience, not me speaking in terms regarding ALL users).
I just can't shake the feeling that the lack of Bertrand Serlet on this project didn't help. OS X up until Snow Leopard never felt bogged down or thrown together, but at times sadly Lion does.
Sure, I'll miss iCloud support since 10.6.9 got scrapped by all accounts, and autocorrect is a nice feature when typing (at times), but sitting here on Snow Leopard right now, my Mac feels like the Mac I loved to use, not the one I sat down and tried to force myself to use when on Lion.