I've tried the multitasking on iPhone and its horrible. Firstly, let's get things straight, it isn't really multitasking but instead suspending the application until you get back to it, however after 2 or 3 applications open, performance really degrades, the phone heats up and battery drains ultra quickly. I would say twice as quick as the N900. I had to uninstall Backgrounder in order to get the phone back up to speed.

The N900 is a true multitasking monster vastly superior to any other pseudo-multitasking phone out there.