Halo 2 Vista is plagued by a bunch of ridiculous shit. It's a pretty bad port, all things considered. Like 16 people play it.
Halo PC/CE still holds up reasonably well. The netcode leaves a fair bit to be desired, as it was designed with 56k in mind. However, the population is still there. Copies are relatively easy to come by. It's $20 on
Amazon.
The modding community is still mostly alive and the player base is still there. The only issue is that they're seemingly trapped in some kind of time loop from the early 2000s, where people used MSN, AIM and Xfire. A huge chunk of them are also from Mexico and Brazil with the internet speed to prove it.
So, I mean, it's there if you want it.