The D-Links provide a very usable low cost per port for non-critical Item. I also have a few Allied Telesyn switches for this reason that work just fine.
I find the Compaqs very good for my needs. These unit cost over $20K not that long ago. A lot of the data infrastructure in the world is done on the Proliant line. A lot of people badmouth them because they don't really need all the manageability that I do. I can run diagnostics on the newer boxes when they are not even running. Out of band management rocks and is accessible via web interface to me across a VPN network.
OO is hosted on the upper of the 2 older Proliant servers. The 6500, the one below it is a 3000 and is used to collect logs, statistics, and some side duties like hosting backups and secondary DNS. The System above them is a Dell Poweredge server similar in processing power to the Proliant 6500. Both having 4 XEON 550Mhz processors and a couple GB of ECC SDRAM. The poweredge lacks the RAID ability. I use it to run What's Up Gold for network monitoring of me and my networking customers in the area. It will also hopefully be the server for my new DNA passwork cracking system. Handing out jobs to the 100 wkstns that will use their idle time to crack passwords for me. If it can't handle it then I will be adding another server for that.
The newer HP Proliants are use for purposes that will remain undisclosed for now. Directly above them is the PIX 515 firewall and below them the Cisco 3550 that is my core switch.
Of course there are a number of other systems and switches not to mention numerous connected remote networks. Including my little NOC down the road at my house. For the most part I could do 90% of my work without ever leaving the house. Maybe if I get enough minions that will be my future. I could even get rid of my car and cell phone.
The 6500 has a much newer version of the RAID card because when we were testing it in hopes of moving gonegold.com to it we found the file transfer rates didn't give us the expansion ability we wanted.
Oh almost forgot. That is a fiber patch panel in the top right of the first picture, and the backup autoloader between it and the D-Links