it depends mainly on the device......but android (froyo) has the best streaming so far that i've seen.

PROS of Android:
-100k plus apps
-many developers and open source software (has a CONs below)
-easy to use (user friendly)
-also for geeks (many hacks etc and most of them are only one-click)
-paid apps are tied on your android account w/c means even you switch to a different android device, you can still re-download your paid apps without any charges.

CONS od Android:
-multi tasking works sucks (apps dont close entirely even you exit/force close an app), and not real multi-tasking.
-too many available devices (when you say android, its picking from samsung, htc, motorola, Acer, LG, SE, etc) so you need to choose the device carefully.
-the email and VoIP accounts is quite errr....limited for now (unless developers will make apps for more)

Things you will miss from MAEMO to Android:
-real multi-tasking
-Maemo is more open-source.
-media player (n900 can play a LOT more media files than my SGS)
-Xterm app (on android, you'll need a pc to edit some root preferences)

above statements are based on my experience having both android and maemo

if you are an average n900 user, switching to android is okay and maybe more beneficial for you. I admit that the n900 is not as user friendly as other Nokia Devices or other manufacturers.