You'll want to check that its cell network hardware is still supported by your carrier in your area. For me, I'd have to switch carriers to use the N900 as daily driver again.

GPS works, but should work better if you get the AGPS fix to work properly. I haven't spent enough time on it to sort it out, but I think others have. Power search these forums for some info on that issue. And Modrana is still under development on N900! Using it in the car was always a pleasure, since it perfectly fit the "easel" formed by opening the dashboard compartment that occupies the space in my vehicle that would contain the optional Navigation screen.

Last time I used the N900 for a week (before AT&T pulled the plug on 2G GSM) battery life was ok for a full day. YMMV. And who knows how the previous user(s) took care of yours . . .

The web browser no longer works or works poorly with many websites these days. Again, YMMV depending on just what websites you use. I never found the N900 to be all that well suited to one-handed operation -- just IMHO. [For me, the N9 was kinda the pinnacle of one-hand usage, just big enough to read, not so big as to risk dropping (in the toilet, perhaps, not that I'd do that) when scrolling with a thumb and gripping it with your palm] The best thing I've found to do on the sofa (with the N900, that is) is to use both Pierogi for IR control of my AV equipment and XBMCRemote for my Kodi (fka XBMC) over my wifi. That IR emitter is perhaps the 2nd most awesome thing about the N900 after the keyboard.

Other members will probably have other interesting observations and ideas for you with using your N900 in 2017. There have been a few threads about this subject in the past you might look through, but stuff changes in the smartphone and online world right out from under us whether we like it or not.