They're reliable -- very reliable, in fact -- and a have a good management interface. They're simple to use and quite easy to understand, and I like that they're not CLI. It's the proper GUI interface that makes them much easier to use rather than just having the CLI which makes some of them very difficult. Cisco, for example, is only CLI, but HP gives you a GUI.
They're also very configurable and they're very good.
Improvements to My Organization:
The main benefit is reliability. The switches don't go down and they tend to last for a long time. They just don't go down.
They also only rarely need rebooting. I can probably count on one hand the number of times we've had to reboot an HP switch.
Room for Improvement:
They are very noisy, though, and the fans tend to get more and more noisy as they go along. The noise is actually a pain because sometimes where we've got multiple floors, we might put a switch on each floor rather than just put them in the comms room, and there the noise is an absolute pain. They are just very noisy.
That's why we like them, because they're stable. They're very reliable and they just last. The PO switches are also very good.
You can scale by adding fiber connections to the switches which makes it simpler to join switches together, but we haven't found the need for it because the switch is so configurable.
Other Solutions Considered:
Yes, we have used competitors. We have used Dell, which is absolutely lousy. D-Link has some high-end switches, but they just don't come close.
They're not Cisco, and big companies want to see a name like Cisco. True, HP isn't Cisco, but that's a bit unfair. Having that said, we've got one very big company now with about 200 users who are getting rid of their Cisco switches and putting in HP's.
They're doing so because of HP's reliability and because they got fed up with paying Cisco prices to get their switches and to configure them when any network administrator can configure an HP switch. With Cisco, you need specialist knowledge and you don't really have to have specialist knowledge just for a switch.