I played Halo on the XBox One for the first time today. Prior to that, it was always on the XBox 1 (2001 version) or the 360. My primary impression is that it's still really buggy, and while it can be fun locally, if you want to play online you're better off just getting a 360 and playing it there.
Noteworthy bugs include:
- Poor netcode, leading to lots of rubber-banding. Halo was always poor in this regard, but it was much worse than usual with the One.
- Even when the graphics were fluid, it took a few seconds to notify of kills, which led to many situations of being unsure if you actually got the kill or not.
- Joining other peoples' games via XBox Live was quite flakey, much more so than on the 360.
- There were a number of times someone died, had a respawn timer, and the respawn timer stopped at 3 or 4 seconds for 10-15 seconds while the game kept going on.
- Turning off the console didn't really turn off the console; at one point Halo froze, so we restarted the console and it was still frozen. We had to unplug it to fix Halo. Perhaps technically not a bug, but not what we expected and inconvenient.
- The XBox didn't remember the WiFi password and it had to be re-entered every time we (completely) restarted it. On the plus side, we've got the password memorized now.
As for the graphics, I like what I've seen of Halo 2 Classic more than Halo 2 Anniversary so far. The former does a better job of setting the atmosphere; the latter has more details but for no real benefit in atmosphere or gameplay (if anything, it's harder to distinguish players from backgrounds). Switching back to Halo 2 Classic, it felt like you were playing Halo PC, but with split-screen and a console controller... which was a good thing aside from the above technical issues.
After awhile we gave up on XBox Live and decided to do co-op campaign, starting with everyone's favorite level of The Library. This was actually a lot more reliable and in some ways more fun, which is kind of bad since The Library is not actually everyone's favorite level, but the most infamous one in the series.
So on the whole, I can see how Halo and Halo 2 could be a lot nicer on the One than the 1, but currently there are enough issues that I'd recommend anyone new to the series buy a 360 instead, should they seek XBox Live multiplayer, or an XBox (2001) if they seek local multiplayer (the XBox has better performance than the 360 on Halo 1/2 since it runs natively rather than through an emulator). The new one may well be better in a year, but it isn't yet.