Use of Soundboard

Wondering if anyone has used what’s referred to as Soundboard in place of Homosote ? It appears a bit softer, not sure if it’ll hold the spikes well enough or any other pros/cons. Thanks

We used two layers of sound board on the Cochise & Western Model Railroad Club’s 20 x 40 foot HO scale layout, glued in place with caulking compound and weighted with concrete blocks and other heavy weights until it set. On our HO scale portable modules, we have one layer of sound board. I like it much better than Homosote because with 1" thickness you can use sewing pins to hold the track in place instead of nails. Sound board is easy to carve into for depressions, ditches, or whatever, and it doesn’t buckle or swell up if it gets wet during the scenery making. We even saved the sawdust from cutting sound board and used it as a filler in the scenery plaster. Sound board is also much cheaper than Homosote and is easier to find.