This is only a gut feeling but I might put it this way.. "I can't see Android on N900 ever being 'better' than Maemo 5."
I'm not sure now, but has Android ever been ported to any phone originally running some other OS so that it would've had more features, reliability, support and applications? It's a non-trivial job and even big manufacturers like SE seem to be having trouble with it.
I'd guess a community port of Maemo 6 on N900 would be more feasible and worth putting work into? Though your mileage may vary and all that jazz..