With a rapid decompression, I'd suggest it's a case of get down to 10,000 ft or MSA (whichever is higher) ASAP. Better to blow a few eardrums down the back than have them die of hypoxia (even with the oxy masks).
If there's structural damage (fairly likely in the case of a rapid decompression in a widebody), then you'd probably want to limit your speed rather than accelerating to Mmo/Vmo during the descent. That would certainly reduce your rate of descent, but with some aircraft there's the option of lowering the gear to add some more drag at the lower speed.