I'm not really that interested in these sorts of discussions but here comes my input;
Why are we talking about the AAU? Because that's considered a very important "metric" for the Big 10, right?
I don't believe that there is a hard and fast metric that is required for Big 10 membership.
I think it's something much more like a smell test.
If this is a debate about who would pass a hypothetical smell test with big 10 presidents, I don't think there's any doubt UConn is more of a "Big 10 type" school than UC.
UConn is a major land grant, flagship university. UC is not. The impression I've always had, and someone can correct me if I'm wrong, is that UC is a commuter school. That is a major cultural difference between the Big 10 schools and UC. UConn's public Ivy culture and high academic standards (look at incoming freshman stats and alumni earnings) means that UConn fits the Big 10 profile better by leaps and bounds.
That is why Nebraska got in and Michigan State got in back in the day and why Notre Dame had a standing invitation; those schools just have a big 10 "feel," they pass the smell test. It just so happens that the profile of school that the big 10 is looking for often times overlaps with what the AAU is for.
You guys are going to drive yourself crazy (if you already havent) trying to nail down some rubric that the big 10 uses, but it doesn't exist.
Anyway, having said all that, I don't think either school is going to the Big 10.