Hi,
my private mainsystem is still my A3000T and it usually runs a couple of hours before I turn it off or need to reboot.
Web-browsing forces me from time to time to reboot the machine but with other software I have no problems. My main problem for reboots and crashes has been defective hardware (CPU-socket of the CSPPC :-().
Back in the days of my A1000 I left the system on for weeks playing Elite. I saved the games to the ram-disk and just turned on the monitor to continue playing. The A1000 case-fan is so silent the A1000 could run in my bedroom day and night and hasn't disturbed -- in fact the fan can't be heard under normal conditions.
Noster