TLDR: Are attic insulation companies pushing me toward fiberglass batts because it is in any way better, or just because has better profit margins? And what about vacuuming/disinfecting?
Long form:
We're going to get our attic insulated soon. I am in the process of getting quotes, and based on the reading I have been doing, I would prefer cellulose for the cost and increased R-per-inch of material. However the first 2 quotes have all 'strongly recommended' fiberglass batts and a vacuuming/disinfecting (we recently had the old shingle roof replaced with asphalt, and there's debris up there from that). Both of their quotes were in the $2500 range. The third one is coming out this week, but recommended cellulose and gave me a preliminary estimate of $1080.
Their justification for the batts was that "if you have work done in the attic, they will disturb the blown in stuff, but the batts are replaceable." But, we've already replaced the roof and cloth wiring, and I could get the whole thing done twice with cellulose for less than their price. Their description of the cleaning/disinfecting was some vague "best to start with a clean foundation" kind of stuff and that the disinfectant smells "nice". I assume larger pieces of debris effects how the batts lay as well. There's no indication of rodents/pests up there.
So, in your opinions, is there anything superior about fiberglass batts that I am missing? I think it would have to be significantly better to justify double the cost. I don't begrudge anyone making money where they can, but this seems excessive.