Just upgraded iOS 4.2 Beta 1 on my iPad last night. I was using jailbroken iOS 3.2 before. Here are some of my comparison: 1) Multitasking: In general I like iOS 4.2 better than Backgrounder+Circuitous. One reason is that I never get Skype working in the background before. Now I can use skype while at the same time browsing the web etc. And my feeling is that the iOS 4.2's background mechanism consumes far less power. However, I do miss part of the backgrounder that you can customize each individual app to control whether they will run back-end or not. In iOS 4.2, you always see lots of icons for last running apps and it looks cluttered after a while, and you would need to remove some of the apps from the list,which is quite painful. For me I think only a small number of apps really need to be running in the background all the time. 2)Folders: iOS 4.2 is better than Categories and CategoriesSB IMHO. Adding apps to and removing from the folder is much easier. You can also easily distinguish folders and regulars apps though icons. 3) I miss SBsettings a lot! I miss Activator a lot! I am not used to using Home button now... Previously I always double click the status bar to go back to home screen, and use a slide gesture to switch among apps. I miss FullForce for a few iphone apps I have. Hopefully these apps can come back soon when iOS 4.2 can be jailbroken... Any other thoughts?