The engineering behind the differences in the 4012 and 4072 is pretty interesting...
The 4012 is, of course, the "lawsuit filter". This was the amusing stand-off between Moog and ARP, when Moog accused ARP of stealing their transistor ladder concept (they did), only to have ARP whip back around and accuse Moog of lifting ARP's exponential CV converters (and they did, too). More or less ended in a "agree to disagree" state, but ARP did redesign that filter...and screwed it up.
The 4072 is the "post-lawsuit" filter, and its mellower, less edgy sound comes from a circuit design mistake that rolls the response off between 12 - 16 kHz. It was released anyway, as the voicing IS actually pretty neat if you're shooting for a mellower result. But until the recent releases and DIY clones, you never really had the two VCFs side by side unless you happened to have two different 2600s. To my ear, the 4012 is the go-to for bass and really cutting leads, while the 4072 works great on pads and countermelodies.
Still kinda wish they'd put in the HPF from the Odyssey, tho...