This is somewhat interesting and some of the comments are truly frightening. From the perspective of a Pans Ops procedure designer, here's the basic criteria (very basic!) for an aerodrome at 1,000 feet AMSL.
Cat A IAS 100 Circling Radius 1.68 NM
Cat B IAS 135 Circling Radius 2.66 NM
Cat C IAS 180 Circling Radius 4.20 NM
Cat D IAS 205 Circling Radius 5.28 NM
Cat E IAS 240 Circling Radius 6.94 NM
Little wonder that the FAA is jittery about circling in a jet within 1.7 NM! I'm given to understand that the FAA has admitted the problems associated with their TERPs circling criteria but, after all these years, despite prangs off circling approaches, they're reluctant to change! So all they do is discourage circling... interesting.
As to the difference that was initially discussed between circling MDA for a ILS/DME and a VOR/DME approach, I can't imagine it unless the VOR is offset toward terrain AND the MAPt for the VOR/DME procedure is in a position that is far removed from the final approach course for the ILS/DME. Without seeing the procedure and the way it was designed - including whether Pans Ops or TERPs - it's not possible for me to comment further.
For those who are heroic enough to be able to circle at 200 knots, or thereabouts, within 1.7 NM, I say more power to your elbow! For my own part, I would much prefer the greater safety afforded by Pans Ops procedures.
As to the way to go missed approach off a circling manoeuvre - no matter what nomenclature is applied to it under the FAA system - I don't see a major problem in turning back over the runway at the outset. The only proviso I would add is that, if you've already descended below circling altitude, or you can't turn pretty sharply, you better be able to pray to some sort of God.
And, of course, all bets are off if you lose sight of the runway during the turn toward it. Still, it's better than nothing.