Oops, a few personal thoughts that got a bit long.
Spoiler:
]I have always been a bigger fan of Ayu than ABC but I still like ABC very very much. And this time around he actually have a better album than Ayu. All according to my own personal taste of course.

Ayu didn't click as much as she often do with me this time. Even though I've been a fan of hers for over 10 years, cried, seen her live, have this crazy big Ayu collection with almost all her releases e.t.c I cancelled this album right the minute I saw the covers (and I really needed money because of that stupid dentist, argh). After listening to the album I still like the middle part, I love reminds me + Tell me why, I enjoy the jazz parts and skips the first and last songs. Anywhooo...
I might have found that I'm not the only one who "clicked" with this album even though we love Ayu and all because of different reasons. This doesn't say that the album is bad, just that it's not our taste? I also don't think the covers helped her out this time around like others have said. Especially with the divorce e.t.c.
ABC have a solid album and had a really nice promotion that went on for almost a year. It is supricing to see him selling higher than Ayu but I would actually be happy if he got that well deserved #1 spot with this. But I'm sceptical, Ayu have an amazing crowd of fans who support her and I think this will be a hard fight in the end. ABCs numbers will fall faster than Ayus. She's steadier.
Either way I'm super happy to see both of them in the top because I don't really bother about sales anymore (even though the music companies really does and it will affect artists too) but for my personal care I'm not bothered. I'm just really hoping Avex won't put an Ami Suzuki on Ayu.