I own the 4 and had the 3. Stock, the 4 is much quieter, slightly more efficient and very comfortable. I would not call it loud by any account, though louder than any DM or other spool.
Proud BOB WHITE Prospect
ANTIDOTE Twister LV1
2015 BPS Twister Autococker
Bob Long MVP
Bob Long Flame G6R
Palmers Brass N' Wood 1K Blazer
Sterling Pump & NSG Splatmaster
Coming soon... Niche Element pump "Rasta Ahoha"