I have also experienced most of the issues mentioned at one point or another, but generally I find it works very well. I have noticed that the built-in rss app+widget cause trouble sometimes. However I have also had ~10 web pages open as well as message notifications while still keeping the phone relatively responsive.

I bought a BB Bold 9000 when it first came out and it was a full year before the issues with it were ironed out. I've had the N900 for about 3 months and I think it's going from strength to strength.

It can be argued, however, that one of the phone's greatest strengths is also its greatest weakness. The open nature of the phone does mean that the quality of software will vary. It's the price we pay for the freedom we have and we just have to be selective about the apps we use. Not all developers are equal and neither are the apps they produce.

For example, I installed 'Brain Party' from the Extras repository and I found that unless I closed all other apps and desktop widgets (!) it would stutter and run very badly. A couple of days later I got SPBrain Training from the ovi store and it will quite happily run with other programs (and my widgets) in the background and minimize gracefully when I get a call.

Maybe someone should put together a tool which creates a report of all installed apps and memory+storage usage which people can attach when they are seeking help on the forums.