Ok, so here are some things that you will have to do periodically:
- delete call logs. As call logs get larger, the phone's performance as a phone tends to lag considerably. There are apps that can automate this, or you can clear them once a week or so. If there is some reason why you need to keep call logs, there are apps that can back them up for you.
- the same with SMS and MMS messages. The larger the message store, the slower the phone will be, and, if the number of messages gets too large, it takes a long time to delete them. Agan, if there is some reason why you must save messages, there are apps that back them up, either to your SD memory card or to gmail.
- in my experience, the browser tends to close when it is first opened after the phone has been running for a while. This can be fixed either by restarting the phone, clearing the browser cache, installing an alternate browser app, or just living with it (it will always open on the second launch.) This happens whether you launch the browser from it's app icon or if it is launched when you tap a link from another app or email message, or open a bookmark from the bookmarks widget.
Otherwise, the phone is pretty solid. Don't install too many apps and you will be fine. Be aware of the trackball issue and be careful when you press it, if you ever do, and also be careful with the USB power cable - the trackball is just above where the cable plugs in and I would think that moving the socket too much, by jiggling the usb cable up and down while it is plugged in, causes many of the trackball problems that people report.