I think that the truly legitimate problems are few, with those encountering them having the loudest voices.
Other more frequent problems come people installing apps (from devel, maybe even testing repos) knowing very little how to resolve what problems these apps might bring with them. It is only logical for them to be more active in forums looking to be spoon-fed solutions to what they just installed.
Based on experience, the N900 has proven to be stable, and is THE phone for me (me being an utter noob). The N95 was a much lesser unit when it first came out, only becoming a success after several firmware updates.
Out of the box - nada, dropped in a new sim at T-mobile and I was up and running.
Had to add some apps to tweak it more.
Only quirky thing now, which just happened (3rd occurance), if the n900 is left in phone mode with dial pad and a notification pops up (sms,email as far as I am aware) the Media player starts playing from where you left the last song and will keep playing if its a playlist or shuffle all from last selection. I only did a quick search so far but did not find anything if its a setting issue or bug.
(I tested again, set it at phone, and emailed myself - started playing lolz.)
Prospective buyers of an N900 might be interested in this post where I attempt to objectively sum up my experience with it after owning it for 6 weeks.
I have been using my N900 for a month. I did not have any problems mentioned above.
Only two features I miss - Those are from SW side and I am sure that they will be upgraded over a period or may be in next release
1) USSD is missing
2) Not able to control media player using button of my handsfree (volume or changing tracks)..
HW side no problem at all. I made many of my friends jealous of me. Few of my friends call me "Brand Ambassador" of Nokia because wherever I go..I only talk about my N900.
The device is awesome!
I was scared because the device is not sold and supported in Chile. So I thought if it is as crap as described by the few very loud on this forum I will be (insert swear word here)
However it is the nature of things. I believe there are probably already millions of users (at least one m) and if some have problems they will come here. Some problems will be real, others will be fakes and others will be users who have problems with themselves. My favorite (not) thread was a thread "I hate this phone" but the guy was not willing to sell it. This was as the phone was in back log and he would have received more than he paid for.