Any opinions on Floormuffler Underlayment for underlayment?  Or other preferences? 
I don't love that it has adhesive strips (trying to go nontoxic) but it seems to have good reviews.  This is for a floating wood floor

wood floor over what? Check out Tyroc sufloor too.

over two inches of concrete that has radiant heat tubes in it
we bought the floor muffler - haven't used yet but hoping it's fine/good product

Will the Floor Muffler insulate you from the in-floor heat you want?

Floor muffler claims it is great with radiant but...that's why I was curious what others thought of it.

this is what they claim:
Built-in moisture barrier - no additional film required; Ideal for radiant heat flooring .