He's absolutely correct about Halo. The single player game is not all that great like the first title (maybe it is on Legendary and co-op, but I haven't done that nor do I intend to), but the multiplayer is an absolute blast. Seriously, it never gets old. I much prefer System Link/splitscreen modes to Xbox Live personally, but one thing I love to do is watch people play on Xbox Live -- I think it has a very solid spectator appeal that is also present for splitscreen games.
As far as GTA goes, it definitely isnt perfect but I'm personally having a great time with it and find it to be far and away the best title in the series (and also the easiest, but that isnt a complaint per se). Yes it has some graphical glitches and yeah there are still flaws with targetting and the like, but the missions are so well executed and the cutscenes are just an absolute joy to watch. The liberal use of foul language helps A LOT as well -- it's like watching a cop show on NBC after The Shield, it just isnt the same. Overall though, his assessment of both titles is for the most part pretty spot on.
And it sounds like his position on DMA titles hasnt changed much since Body Harvest.