Since several thousand heat load studies, it appears wet spray cellulose also has an additional feature:
Enough money to off-set some additional cellulose costs up front is relative to LESS COSTLY - framing, -enclosing, structural-building that may leave some acceptable-GAPS and/or LOOSER, faster construction on a SMALL PORTION of home building (if reasonable). {just if applicable} Structural re-enforcing of ceilings under.. is noted by others and Dana in several other threads for that r(50) + attic of cellulose.

To ~ 90% to 92% (?) may be reducing leaks is great, however cellulose it seems does breaths enough also that final results may naturally lead to less erv needs. Some inspectors allow for absolutely no outside-type vapor barrier needed.
- it will be interesting to see comments on that. -just seen that remarked about over the past 14 years.

x) If your inspectors requires the interior vapor barrier---, as some did 2004-2010, (done here !) - maybe slice it open or off after , ... and you may want to do that as before interior drywall goes up. period. Dana is very right-
avoid a terrarium tantrum.