I haven't had any issues in safari, if anything it has been a much smoother experience on my machine. That said, I use glimmerblocker to get rid of ads, which prevents a bunch of the crap that generally slows page loading down.

Simba's suggestion of click2flash will help as well, I do get the "Flash Plug-in Failure" once in a while, so I may consider installing that myself to prevent flash from loading altogether.

For you guys with older machines, Lion will be tough to run, even with 4GB of RAM you can still run out of memory quickly. I've got 8GB and it isn't always enough when I've got a VM or other heavy tasks running.

 

I ended up nuking mine and reinstalling SL. Lion caused a lot of hangs, some printing problems (could be the driver, but the updated "Lion" driver for my Canon printer still wouldn't print out of Preview -- would print from every other app, but hung in preview). Lots of spinning cursors. Much happier back in Lion, everything feels faster. I don't have a slow/old Mac either, I'm running an i7 27" iMac w/8GB Ram (granted a 2009, but still it should run Lion fine).

I'll wait until a later release and maybe try again, but Lion was definitely hurting my productivity and this is my Mac I use for work.

 

I've been using Macintosh for nearly 12 years, and I have never had an issue with either Snow Leopard (except "random hangups") and Lion (so far ZERO issues, and on for 6hrs + a day) I'm not your "average day" Macintosh user; I use every bit of what they're made of and I've never seen an OS so complete and versatile like Lion.
I have a 2011 MBP w/ Core i5, 8GB RAM and a 120GB SSD and it runs FLAWLESS. Even when I had the OEM 5400RPM HDD it ran excellent! I don't see where people are having these "issues", try doing repairs within Disk Utility (i.e. Verify permissions/ repair disk permissions or verify disk/ repair disk)
I remember on my 2009 MBP Core 2 Duo I used to have random "hang ups" at times and I did those methods and it cleared all of my issues.
Anyways, I don't see why people would go back to SL, kind of like why people went back to Windows XP? But who knows, maybe you're having an OS issue so backup and do re-install, mate!! +1

 

I think a lot of people have issues because they're on older machines without enough RAM or with slower hard drives. My mid 2009 MBP is showing its age with Lion installed, but I think the SSD and 8GB of RAM that I installed mask the machine's slowness enough for it to be usable. I imagine it must be pretty sluggish on an older white MacBook or something of that nature.