FWIW I use my N900 for communication all the time, calls, texts, MMS are probably the most used things after the media player and the GPS.

All these work perfectly well for me, most returning users will feel at home returning to Maemo UI.

I still get several days from my N900's Polarcell with fairly average usage, so I can only assume something was chewing your battery life.

An issue with the N900 from a user perspective is you have to be careful how you use it and what you install on it. Going to Extras and installing everything will no doubt cause slowness. I found out very quickly that less is more when it comes to "apps".

Yes, browsing is clunky but I am getting good results from QML Browser at the moment. Opera has always been operational for most.

Also yes some devices have issues with the USB port, but again we are talking about a returning user.
The device isn't for everyone but for many here, myself included, there isn't anything else suitable, I would say if your considering returning then your highly likely to put up with it's quirks over the other offerings.