There's some nice stuff about Avocent KVMs, but I've been turned off by their false advertising. In particular, they claimed that I could daisy-chain their switches together and have one menu show all of the connected consoles. Apparently that simply wasn't true, at least with the models I had, despite the fact that it was explicitly in the documentation.

Also, the KVM-over-IP software is exorbitantly priced, after you've already purchased the KVMs, which are not cheap themselves. The dongles are pretty pricy, too.