Argh. Is that right? I don't use the email app yet, I have to wait for it being able to download headers only. It MUST be possible to read emails while offline. I, for example, used that feature with my N800 to once handle a problem with my flight, in an airport in the other hemisphere. They could only resolve the issue with a number that was not printed on my flight documents. Fortunately I could whip out my N800 and find the email that I had just received from the travel agency, with that number. I had previously been networked back at the hotel, that's why I had it. Couldn't do that at the airport. Not with the the N900 even - you just don't go data roaming on 3G (ha! as if there was 3G, or even working GPRS in that country) when outside EU (for me).
UPDATE: Apparently this was false alarm - phuh! Ref. zehjotkas's posting below. As I said I don't use the N900 email app yet, it needs to be able to download headers only, when I choose to. When it gets this feature I'll start using it. So I'll change to this missing feature as my biggest gripe with the email app.

Fortunately that's probably something that'll come. And it's not a show-stopper (unlike the gripes with the mail application).

As I've understood it, GPS only really works while online. I never planned to use it, I prefer a proper quality external BT GPS like my Holux. Occasionally (when I accidentally hit the map application) it tries to switch itself on, and it looks like the only way to get out of that is to reboot the device. As far as I'm concerned the GPS is rubbish junk and could have been left out of the device altogether. Do it right (i.e. use a proper chipset, not the silly TI GPS chipsets), or don't do it at all.

The only unresolvable hardware issue I noticed right away is that it's nearly impossible to use the N900 w/keyboard while on the couch..