If your iMac is capable, I would add more RAM before upgrading to Lion just to be on the safe side.
The best new feature of Lion in my opinion is the gestures, which you probably won't take advantage of on an iMac unless you purchase the trackpad (is that what they call it?). The new mail.app is really nice as well.
The iMac is maxed out on RAM. I only have the wired Apple Mouse.
I have a Mid 2007 iMac 2.4 Ghz with 4 GB RAM.
I too have a mid 2007 iMac and according to this: http://support.apple.com/kb/HT1423 4GB is the maximum RAM we can run.
That's as much as Apple would support, but as I said, you can put 6GB in it.
That's interesting, as even Crucial says that for my iMac: http://www.crucial.com/store/listpa...Hz Intel Core 2 Duo (20-inch) MA876LL&Cat=RAM 4GB is indeed the max.
I was speaking with a friend who has this exact model, and upgraded from 4 to 6GB after two weeks of running Lion on 4. He said the difference was not enough to impress him. If he had to do it again he said he wouldn't.
Frankly I was surprised, since there hasn't been a single time I've added more ram that it wasn't a very satisfying improvement.
I was speaking with a friend who has this exact model, and upgraded from 4 to 6GB after two weeks of running Lion on 4. He said the difference was not enough to impress him. If he had to do it again he said he wouldn't.