"Runs great on my 2009 17" Macbook Pro"4.5 starson by direct225
Pros: Love the new notification and voice dictation features.
Cons: Haven't found any yet.
Summary: I upgraded the RAM from 4gb to 8 gb right after I upgraded to Lion last year due to my otherwise fast running Macbook Pro running very sluggishly after the upgrade from snow leopard. It still ran slower but acceptable even after the memory upgrade. After the upgrade to Mountain Lion I noticed an immediate improvement on the speed that different programs loaded. It's only been 1 day but the computer seems to be running everything faster. I would recommend Mountain Lion.