DH and I are renovating a house and will be putting bamboo in the kitchen, downstairs office, two hallways and upstairs master bedroom. The downstairs rooms are over a crawlspace. We met with the flooring subcontractor today who has installed Teragren bamboo in the past. He initially recommended floating the floor, but said he'd glue it down instead if that's what we wanted. For the floating floor he'd put down plywood and a thin pad which he said would help keep the floor quieter when walking on it. Each option would cost about the same - the cost of the pad vs the cost of the glue were very close.

Which option would be preferable?