Now in my fifth year using the BBB method. Not everywhere, but I would say 90%.
For me, I cite four very important reasons BBB works and has a good ROI:
1 ... It separates the native soils from the sand 100%, which in Arizona, California and many Western states and areas is essential to prevent rocks and blending of the two distinct ingredients; where an un-lined bunker or a bunker with a soft liner may have to be re-worked in 6-7 years — except for replacing sand, a BBB bunker will probably last 20+ with the ONLY maintenance being sand replacement
2 ... With a hard liner you never have to guess at sand depth; we have inherited bunkers with 4-5 feet of sand depth because the club just kept, over the years, adding and adding sand; with BBB there is NO guesswork as you have with soft liners (fabric) or no liners, you simply probe the bunkers and buy as much new sand as you need — no more
3 ... The bunker shape is also set in stone (pun) — migration of bunker edges with BBB has to be purposefully changed as opposed to changed at the hands of staff
4 ... Drainage is virtually fool-proof because the porous polymer/stone layer serves to move water both laterally AND vertically toward the low/drain point(s) of each bunker — if anything, we are getting "The bunkers are too dry..." comments, which I find ironic
Most important is to realize that BBB, in most areas where gravel aggregate is readily available, will not exceed the cost of other liner types. While I have used other liners (fabrics and sprays) I am pretty much of the opinion that when a liner is called for, this is the best method...I know how long rock lasts, and I trust the polymer because similar polymers are used in other architectural industries.
When do we NOT use any liner? When there are virtually NO rocks in the native soils and we are confident that the native soils will stay put and not heave or become expansive below the sand. Del Rio CC in Modesto CA is one such place. The site is mostly fine sandy soil, and it is stable. The sand used in the bunkers has proven stable with very few issues in forming a soupy mix with the sand and soils "becoming one" after time.
P.S. I am not sure TD's comment is crass...maybe just a bit
snarky. What I take exception with is the notion that it lines the pockets (pun) of builders. Contractors likely make more money preparing subgrades of UNlined bunkers (all labor) as opposed to simple finishing the floors and spreading products that they have to procure. A mark-up per s.f. is not as rewarding as labor per s.f.