As hard as it is to admit it, I'm siding with 343 on this one.
Bungie had created Halo in the first place, so that obviously gives them some points. But it seemed like as the games went on, the creativity and those engaging vibes that were present in the first game started to die down. Reach, while fun, just seemed a bit dull, plain, underwhelming. As if there was no soul put into it. (Which I am not claiming, that is absurd and I am sure the folks over at Bungie did their best with the game.)
For me, Halo 4 was a long needed return to form. A brand new, devoted company with fresh ideas took over, and it shows. The vast Halo universe presented by the books and barely touched by previous games were finally touched upon and made relevant. Rampancy, while mentioned in previous games, really felt like a serious threat here. Bungie loved the idea of Rampancy, and I don't get how they didn't include it in any games.
Obviously, this is all my opinion, but I really do get the same vibes while playing Halo 4 that I got while playing Halo: Combat Evolved. I truly felt like I was exploring an alien world, and everything was so fresh and new. If Bungie kept going on, I'm sure it wouldn't be like this, sadly enough.
So, with all of that said, I'm glad 343 took over, and at the moment I prefer their work.