It works with TMobile data (I'm using it on TMobile). And it doesn't have bad battery life compared to the n800 (though there are apps and widgets out there that will suck the battery out with constant updating). I was saying that the benefit of carrying two devices is that you don't rely on them to do both.

E.g. if I carry my camera and a DS I can shoot all the pictures I want, then play all the games I want. One function does not influence another function's activities. Yet if I do so on my N900 then I compromise because shooting pictures will use up battery, playing games will use up battery.

Hence if I were to use my N900 as I did my n800, I would have no device to receive phone calls from my mobile # since my data plan I have on the N900 is with that voice plan (cheapest one). Sadly this will be an issue with any convergent device until they make batteries that last days or months with heavy usage regardless of the platform you choose.