Solaris 10 sparc/intel or linux ?
3. Very rock solid stable.
How do you quantify that?? I've got an old Compaq DL380 running RedHat-7.2 that had 3 outages since it was installed in Sep'01. The first outage was due to moving the system, the second was due to me fooling around with device drivers and the third time was when the power supply died. In between it was consistently getting 500+ days of uptime. Seems fairly stable to me...