Lets see here.. you opened an interesting topic.
Gamespy.
The first to have a functional windows based tunnel. No to very little compression on the tunnel which made for a painfully laggy experience.
To my knowledge the also havent updated the tunnel software since then.
Gamespy does have a nice interface thou, easy for new people, contains a main chat. Thats something gamespy has had down for quite sometime though, they just needed the tunnel.
Overall = Good usability, bad performance, good userbase.
Xbconnect
Xbconnect has been evolving as the time has passed. Originally it was a little bit harder for the average user to get used to , but now since version 2 the interface has become a fair bit more friendly.
The tunnel performace beats gamespy by far, but latley v3+ i havent been able to finish a game with anyone.
The tunnel seems to have less bullet delay but choopier play.
Overall - Decent usability, Decent performace, Good userbase.
XboxLadder
This was a project of my own to see how the tunnel stuff worked.
I managed to get the source of a program called the Xbox Network.
Started to play around and now the Japanese use it most of the time as they cant use thier charaters in Gamspy and they get kicked out of Xbc for not speaking english.
During the times that i tested it, i noticed smoother performace than Xbc yet there was more bullet delay. Quiters didnt usually crash the game either.
The chat was basic, game hosting and joining was fairly simple.
Overall - Decent usability, Good performance, Poor userbase
Xlink Messenger
I finally got to play some games with this app today, i hosted a game of halo a week ago, but hosting a game doesnt give much of idea of how the software is working. I was quite amazed at the games that i did manage to join thou. I havent played a single game of halo on the net that was this smooth. With the smoothness did come bullet delay, but its nothing much to bitch about.
The messenger format seems to be a fair bit confusing to the users who are used to gamespy and xbconnect , but there is usally a learning curve with almost any software. Once you check it out for a few minutes you can get the hang of things.
With the combination of Xlink and boxlink, this is looking to be rather nice.
Headset support before a game and being able to choose your room from the tv, awesome.
WGN mode in Xlink is looking to be my favorite, this mode lists alll of the current games going on and you can join straight from there. So basically you set you xbox to look for games and they will appear as they are hosted.
Overall= Decent usability, Great performance, Decent userbase.
Out of them all i plan to use Xlink most of the time, i cant get enough of the WGN mode
and Boxlink is just a great addition.
Keep up the good work to all!