before N900.. i am using 5800.ME..
so i will share my experience. may can give u some input

1st time i buy N900. i really pissed off *before i find this Awesome community maemo.org*.. now i'm really glad i have one

- N900 can't install .jar with normal.. (so make sure what app in .jar format really u need) if no.. thats +1 point for N900
- are u often with video call or not..
coz N900 really *no or not yet* hope in fornt camera.. 5800 do more better... but the prime camera in N900 with 5Mb pixel far better in capture a pict even at low light.... 5800 a bit *poor in quality* when capture @ nite or low light...
- and now.. we talking with app..
5800 have good .sis & .jar app with Touch Screen support / some without.. replace by Virtual Cursor.
@N900 enable reposit, extra reposit & extra test.. than start read this Threads in maemo.org .. u will have a lot off fun in your adventure
which N900 can install dual OS or more.. i can't said amount of apps around N900 .. the best part is alot of this app based on Open Source.. we can used.. learn, edit or even make one of this app for own N900 taste
before use N900.. i really blind in Linux.. but thanks to all @ this community & a bit from another place now i can use & learn Linux based OS with my beloved N900 Gadget..
so the conclusion *for me*= N900 far better & really Fun with Adventure of Wow.. nice.. awesome.. but sometimes make u headache.. d*mn error at everywhere or something else.. but this all is parts of fun & learning

p/s: sorry if my english not good