Based on what I've seen this year, I think that the SEC, Big 12 and Pac 12 all are better this season than the Big 10, and the ACC probably is too, regardless of what metrics you use.
Also, I'd be shocked if the Big 10 gets nine teams in this season; it's a struggle for any conference to get nine into the tournament even when it's really good which the Big 10 isn't this year. That would mean that teams like OSU and Maryland make it, and their trajectories are going way down since the start of the season. Right now, I would have Purdue, Illinois and Rutgers as in, and probably MSU, with IU likely. Wisconsin and maybe Iowa probably will do enough in the end to get selected. Northwestern probably won't do enough to get selected, and I don't think that Michigan, OSU or Maryland will have the credentials in the end to be considered.
I still stand by my opinion that when in doubt, the Committee will select a Big 10 school with less credentials over a smaller school with better credentials, so maybe the Big 10 will get nine teams in this season even if it would be undeserved.