You bring up a good point.
Most distortions are built around thier 'crankin amp distortion' sound and simply sound like weaker distortion at lower distortion levels, not particularly interesting....
This is one thing BJ is particularly good at is making a circuit thats useful throughout its range... I am regularly amazed at how much variety there can be in a 'Deestortion' pedal when made properly....
This was the real strength of the BBOD to me - at low drive levels it is a realistically touch sensitive drive, really follows your fingers well. AND as you crank it it gets nastier and is a really good distortion fully cranked.... you could really like it for very different reasons...... and I think the DRD was designed around its lower distortion sound and also happens to nail a cranked 4x12 when its full up....
Kind of the opposite of the heart of the MP Amp which was designed to be fully functional at full volume, so its always going to sound good no matter where its run, with the distortion pedals if you make them so they sound real at low distortion levels then they are probably going to sound great at full drive levels.....
my vote for best touchy low drive is still the BBOD followed by the Honey Bee .... tho the Sky Blue may elbow its way in there for different abilities