Again: The multi-tasking aspect does _not_ slow down the device. If you want to speed up startup etc. you could for example leave out the X-server and run more bare-bones GUI-wise, but then you would miss out on some features. But the multi-tasking does _not_ slow down the N900 (or any of the earlier internet tablets).
They're maemo and MeeGo... "Meamo!" sounds like what Zorro would say to catherine zeta jones... after she slaps him for looking at her dirtily...