TH2 started bringing goodies in 2012.
By now, TH has become the only D1 mod that's grown so vast as to resurrect unreleased quests in an advanced form: Andariel, Horazon, Worms. < these="" are="" 3="" humongous="" quests="" we="" successfully="" added="" to="" the="" game="" so="" far.="" and="" in="" 2013="" we're="" going="" to="" bring="" even="">
Not only that, TH now gives better looting, way fewer bugs, and dozens of new gameplay features.
Oh, plus we added fully functional set items as an outstanding type of items: http://www.youtube.com/watch?v=qpuNhzbiDro
hamachi & kali are... troublesome
a lot of pain comes from using them
tunngle works way better. even on Vista/7 OS, it works well
on a 2nd thought, it might be antivirus soft that prevents mp characters from being created. not sure, but i'd start from there myself
also, if you're running TH from a shortcut from desktop and not by direct clicking thehell.exe in TH directory, there might be problems because the game might not be able to locate mp char.savefile location on your system. by default, it uses TH folder. some people reported that shortcut run causes such problems. i'd try that too.
I don't recall massive problems with people having trouble playing online.
Late discovery "Tunngle" makes it very easy to play in co-op.
Careful study of documentation of thee mod will help a lot here.
I released latest big version about a month ago. Just yesterday - another one, with a small fix.
These days I don't work on TH as I used to half a year ago (8+ hours EACH day). I just have to earn money, and that leaves almost no time for development. I would love to, but I can't.
Another note about nutiplayer. Realise that it's a Hellfire mod. And there's no battle.net-like convenience tools (although 90% of battle.net players are complete morons imo). So, stick to whatever is best option (currently, Tunngle).
Remember: criticism will give you nothing. Suggestions and bugreports will give you a better product in time.
BTW, THteam programmers are still working on TH2 project. This one should have a lot of nice configurable multiplayer tools. Yet, it's unknown when a beta will be out. But Alpha is available.