For me, the most important thing about the N900 is that it's pretty much like a regular gnu/linux computer, even more so than the Pre or Android devices (that also have the linux kernel).

If you're not interested in the Free/Open source aspects, then maybe there is a better phone for you out there.

But... even if you don't care about computing Freedom from a political/philosophical perspective, Open Source can still be the pragmatic choice.

It is more likely that a feature can be implemented on an open platform as opposed to a closed one. Feature development is not going to be at the mercy of company policy, as is the case with the iPhone.

For me the choice is easy, since I regard the Freedom so highly that I wouldn't want a closed phone- or computer OS even if it had better features (I'm not so adamant about it that I'd choose to get a Neo Freerunner phone, though).