I'm not sure what specs you're running, but my late 2006 macbook runs Lion perfectly, I did add some memory (maxed out at 3GB), but that's cheap as chips these days.
(just don't but it from apple!!)
My 2011 iMac is running with buckets of memory, since it's a cheap way to boost performance. (currently 12 GB RAM)
Adding memory is dead easy to do, it takes all of 5 minutes.
Performance wise you'll notice a big difference up to 8GB of memory, anything over that is not really necessary unless you're doing video editing or other memory intensive apps. (I am).
If you have any questions regarding upgrading memory, ask aways
Fido said:
Sounds daft, but occasionally I like to be at the leading edge. So I want to sync all that's possible.
Then Lion is your only option
I'm very happy with Lion myself, not everyone is though, so you should try it yourself for a while before you upgrade all the machines.
(make a timemachine or superduper backup of a complete Snow Leopard install to revert to in case)
I did a SSD hard drive and memory upgrade with Peter (MoL), and installed Lion, he subsequently went back to SL last week.
If you've got hardware that's a few years old, especially macbooks (pro), the SSD and memory upgrade will make it like a new computer again.
Max
