Basically, it's in the title — It works! Go play it!
Edit: If it's [i]still[/i] not working for you — that sucks. But it seems that the latest update has widely been a success according to various sites (i.e N4G, GAF, reddit, etc.) If you are having trouble finding a game after the latest up date, I suggest either trying Team Slayer as it seems to have the largest population, set-up your Xbox for DMZ host, or port forwarding.
http://forums.xbox.com/xbox_forums/xbox_support/f/9/t/214551.aspx
http://support.xbox.com/en-AU/xbox-one/networking/network-ports-used-xbox-live
I can speak for a few friends and myself in saying that search times are now that of the Halo 5 BETA (which is to say — instant). However, a problem now exists where every first game I load into crashes. I have suspicions that this is a result of being in Preview Program as I haven't heard this complaint as of yet. Either way, hopefully this will be resolved soon.
-
Edited by Meowmaumiumau: 3/7/2015 1:26:38 PMMaster Chief Collection has finally left Early Access, hurray! srsly though, it took forever for 343 to fix it. Made it feel like 343 didn't really care about the issue at all or that they focused on Halo 5 rather than quickly fixing an issue, which ruined their reputation.