It looks like trash to me.
It seems like it's missing a lot of basic features that Nintendo's and Xbox's web stores have.
From what I can tell, it doesn't let you sort things alphabetically either for some reason, so have fun sifting through pages of stuff, hoping you didn't accidentally skip...
That appears to be a slightly different problem. That appears to be people talking about not being able to redeem a code.
Mine was redeemed and playable for years. Microsoft just took away my license for it (and the licenses of others) as discussed here:
UPDATE: Game is back on my account. MAGIC!
I just ran into this problem today, and noticed other people on Reddit were having the same problem.
Microsoft at some point in the last few days has apparently removed peoples' license to digital copies of Gears of War 3.
I got mine along with...