Boraxo - As a frequent Madison visitor, my nutshell impressions of other Madison options in downtown area:
* DoubleTree is unremarkable: perfectly OK, but showing its age. Used to be no charge for parking in adjacent garage which was a differentiator from most other hotels, but now $18/night. Elite breakfast at in-house restaurant.
* AC is closest to Capitol Square and *some* rooms have amazing view of dome. But looks like any other AC - dark, "cool" and minimalist. Agreed that AC is generally is highest $ option, and I don't think it's usually worth the differential.
* Back to Hilton: I actually prefer the Hampton (believe it or not) 1 block away from DoubleTree > newish (2017? build) and well-maintained, with enthusiastic staff. Great all-day breakfast restaurant within (Bassett Street Brunch Club) though - obviously - not the included Hampton breakfast. Hilton Monona Terrace is also solid option - rooms generally either have views of Capitol or Lake Monona, operating executive lounge (no great shakes, but just the fact it is open is notable); rates can be quite high if conference at adjoining Monona Terrace, but can also be surprisingly inexpensive on "off" days.

Didn't really recognize until typing it out that downtown Madison really seems to be Hilton-skewed, especially with integration of Graduate Hotels and new Embassy Suites opening earlier this summer. Only Hyatt option is HP (really only option in entire metro, with exception of HP in Verona, which presumptively is pitched solely for Epic customer traffic).