If it's a pre 2013 demon I'd make sure to have a good supply of QEV diaphragms handy since they do need to be replaced here and there if you get lube on them. Run them dry for the record.
If it's a 2013, or an older one with the 2013 upgrades, it'll be amazing.
ETEK 3LT, with 14" critical .680 barrel and cure 3 + bolt F/S
DM12 red with matching Boomy F/s