The Xantech box is great in that you can programme it with the RS232 codes to send (for example, to a Crestron system, projector or whatever), but for PC control it could be considered overkill.
I've had a very good experience using the
TIRA USB IR transciever (recieves _and_ transmits IR) in conjunction with Girder. For example, the Xantech URC2 remote was unable to learn the power command for the Plus Piano projector. I ended up sending a code to Girder, and had Girder send the power command to the projector. Works fine, as long as the client has the computer turned on! :)
One other thing to watch out for when using a PC as part of the solution - make sure you have better than normal ventilation, as PCs get damm hot in a closed enviroment. :)
Cheers!
-y