I've got the Formula Pre and I love the thing! I've also got a V-twin, and the Formula is NOTHING like that - if anything, it's a turbo-charged preamp section out of a Nomad... Of course, choice of a preamp is highly individual as the usual caveats about the rest of the rig apply in spades, but in it's highest gain mode the Formula sounds like thunder! Getting the Dual Rec sound is going to depend as much on the
power amp as any preamp anyway imho, but I don't see why you can't use the Formula to push a 50/50 or 2:90 into that zone - the graphic helps too! I can't imagine needing more gain at volume - but like most Boogies (again, imho) you've got to turn up the wick to get it growling! I haven't tried using the "direct recording" features on mine yet...
I love the sounds in this preamp - I run it through a 20/20 with a Peavey Valverb in the effects loop, into a pair of recto 1x12" Celestion loaded 3/4-back cabs, and I've had many complements on my tone with this rig. I would suggest you turn it up and try it out with a good amp and cab setup, and if you like what you hear, buy it! Remember, Metallica used to use Mark IIs, and the Formula is
way heavier than my
Mark IIC+ ever was...