Thinking seriously about this flooring (below), and instructions allow for both floating and gluing on concrete slab. Bought a box to lay some out. Some boards bow up a bit. Unsure how the feel of floating would be in general, with the added concern of flatness of boards. Floating quote was around 3k cheaper.

https://www.lowes.com/pd/allen-roth-all ... 5002072237

Gluing is messy.
Slightly bowed boards will even out when all are laid together. An advantage of a floating floor is that there will be a foam layer that can help for comfort and also to even the floor out, if the foam that you will be using is a closed cell foam, which will flatten out if there is a small height difference of the sub-floor. You could always sand the flooring whether glued or floating.

Another benefit are the short lengths in floating the linked product. They can lay flatter than long boards that could cause problems, unless they have other issues. Common with lower priced products.