I played a few today to test, here's my results:
Game 1 [btb br flag on rats nest] - Laggier than the video I posted earlier in the thread, I quit.
Game 2 [4v4 smg slayer on sanctuary] - Two teammates quit and my third went AFK, I quit.
Game 3 [4v4 br slayer on h2a zanzibar] - The entire enemy team quit when we got to five kills.
Game 4 [4v4 br slayer on standoff] - Went fine, better than usual for H3 hitreg.
Game 5 [4v4 br slayer on guardian] - Almost certain I had host, grabbed shotgun and abused host advantage with unpatched H3 melee.
Game 6 [4v4 ar slayer on pit stop] - Not too bad, just hitreg, which is par for all H3 modes in MCC.
Game 7 [4v3(wtf) br slayer on assembly] - I was betrayed by multiple teammates from the start, I quit after my one non-betraying teammate quit.
Game 8 [4v4 ar slayer on citadel] - One player from each team quit but apart from that a fairly solid MCC H3 game.
Game 9 [4v4 classic slayer on chill out] - Solid match of CE, nothing to really complain about here.
Game 10 [hivemind infection on payload(H4)] - Just a pallet cleanser, I still don't like infection.
Game 11 [btb flag on daybreak] - Game was fine from what I could see.
Game 12 [4v4 br slayer on turf] - Two of my teammates went around betraying eachother but I stuck this one out because the other team were fun to play against.
Game 13 [4v4 br slayer on citadel] - An opponent got trapped into the same spawn about four times but from my end it was just the standard hitreg issues.
Game 14 [4v4 br slayer on narrows] - There was a noticeable amount of lag here but not enough that I shouldn't have been able to compensate, unfortunately I played really poor this match.
Game 15 [4v4 classic slayer on wizard] - My shots only registered about half the time on two opponents who were on the same Xbox and the active camo respawned immediately after I picked it up and died.
Game 16 [btb br flag on standoff] - Slightly too much lag to flag juggle but decent enough that I could run around and carry without snapping. I also died to a plasma pistol EMP burst in this match, haha.
Game 17 [4v4 smg slayer on sanctuary] - Two of my teammates quit and a member of the opposition quit. If I didn't get betrayed twice at the start my team would've won, yay.
Game 18 [4v4 classic slayer on damnation] - Game ran pretty well, got an exterm kiltac this match, not many people know how to play H1 I guess.
Game 19 [4v? smg slayer on warlock] - The opposition started with three players and then got one added about two minutes in. One of my teammates quit. Little bit of lag but not too bad. Game 117 for me overall.
Game 20 [4v4 ar slayer on orbital] - Normal hitreg issues.
It's not too long a session but it's the longest Halo session I've played since early 2013.