I got my iMac 24" if memory serves me in 2008 and I've upgraded to Lion OS early this year. I didn't really notice too much in the way of a slow down or feelings the machine was unprepared for the OS and use of newer features besides having to download flash to support my Adobe CS3 Master Suite. My concern is if I upgrade to Mountain Lion will it be negative either in day to day iTunes, iPhoto, Safari or with the use of CS3. I don't want to have to go out and upgrade the machine and the Adobe products if I don't have to as that is likely a $4K prospect. Should I upgrade to Mtn Lion or stick with Lion until and or if I upgrade the machine in the next 8-12 months? Will I gain anything with Mtn Lion?