Great review as always, I felt exactly the same way about an hour after starting the game. The inventory system was awkard and unintuitive and the sidekick seemed an entirely unnecessary aspect (I hate sidekicks in nearly all games).
However:
For any players irked by the inventory system (or worried they will be if they play), situations like the one yahtzee mentioned arise quite rarely (for me at least), and the most important aspect to remember is that you can access your items instantly via use of the d-pad, making it very fluid when you get used to it.
Though i don't like the idea of a sidekick so much, she becomes much less annoying after you get used to her habits and can adjust her inventory accordingly (ie. if you want her to use a machine gun, i tend to give her a machine gun and no other weapons). The lack of ability to give tactical commands (wait here, go there, etc) is a little annoying at times, but i circumnavigated this problem completely by having a friend I play a lot of co-op games with.
In my opinion it's a brilliant game, even moreso in co-op (it's not exactly shoehorned in; it works very well with the game and you quickly find yourself tacticising with your ally to tackle the various situations). I did indeed get it on the midnight launch and me and my friend are on around our 4th playthrough now (short game but plenty to unlock).
As with most of Yahtzee's reviews, right on the mark in many places, but i'd urge you to not take it too seriously as you could well be missing out on a seriously great experience for the sake of a couple of minor annoyances.
