Feedback for the Linux crowd.
I have a tiny N37L - best buy ever. Upon getting it, I recycled the memory and 250GB disk to a PC. I put in 2 x 2GB DD3 1333 PC memory (non-EC) and 4 x 500GB Western Digital disks.
After playing with it a bit messing with FreeNAS (driver issues with newer releases, older works great) and OpenFiler, I set out installing it as intended.
I installed ProxMox VE, a version of Debian that allows for visualization -
http://www.proxmox.com/
I hate hardware RAID, I chose to use the disks separately and use software RAID1 (sorry HW RAID lovers, I have plenty of scars)
Upon it I spun up a few Ubuntu VM's for testing/dev/QA and infrastructure (Samba file server, Squid proxy, DNS to workshop systems, Apt cacher etc)
I checked the BIOS to not halt on KBD errors and removed the screen and keyboard. Since then it's been running headless. Works a charm except when the power fails (I know, I have a 2KVA UPS I must still install). However a press of the power button, and a few minutes later I'm back in business.
I've spun up/destroyed Windows and Solaris X86 environments in KVM as well from time to time, however Windows is a hog.
The server is totally quiet, only the blue HP logo to show it's actually running. It's stashed into a forget-me corner.
Best buy for a PC, originally at R1,000 when they first came out.
At this stage I either need to get bigger disks, or another for a workshop area where repairs etc are done. I'm contemplating the latter. From time to time they are on specials, I just missed the last one.