You've posed SUCH a complex question. One wouldn't know where to begin. I remember when I first read a review of the Reed tt, it did occur to me that, because of its design, it might well sound best in belt-drive mode. Following on that, I too read a post or THE post where an owner says he likes the belt-drive mode best. Above all, I wondered why on earth Reed would build a turntable with an ambiguous identity.
When you were comparing the two Brinkmanns, did you use the very same tonearm and cartridge with each? If not, all bets are off. If so, then I think you found out which of the two turntables you personally like best. But this is not enough data to conclude that all DD turntables are relatively deficient in capturing the decay of musical notes. However, I can think of one reason why that might be true of some: If the servo mechanism is "overactive", its cutting in and out might obscure details after a transient. This is one thing that may be benefited by the Krebs mod to my SP10 Mk3. After the Krebs mod, the Mk3 is much more open, airy, and free sounding, and in the bargain I think I do hear the trailing edge of notes better. Could be my imagination. (The goal of the Krebs mod is to stabilize the stator so that any twisting movement as a result of servo action and according to Newton's Third Law of motion [for every action, there is an equal and opposite reaction, etc] is reduced, because such movement can trigger yet another servo correction, as the servo tries always to keep speed constant. The net effect of the Krebs mod is ideally to reduce the number and frequency of servo corrections.)
When you were comparing the two Brinkmanns, did you use the very same tonearm and cartridge with each? If not, all bets are off. If so, then I think you found out which of the two turntables you personally like best. But this is not enough data to conclude that all DD turntables are relatively deficient in capturing the decay of musical notes. However, I can think of one reason why that might be true of some: If the servo mechanism is "overactive", its cutting in and out might obscure details after a transient. This is one thing that may be benefited by the Krebs mod to my SP10 Mk3. After the Krebs mod, the Mk3 is much more open, airy, and free sounding, and in the bargain I think I do hear the trailing edge of notes better. Could be my imagination. (The goal of the Krebs mod is to stabilize the stator so that any twisting movement as a result of servo action and according to Newton's Third Law of motion [for every action, there is an equal and opposite reaction, etc] is reduced, because such movement can trigger yet another servo correction, as the servo tries always to keep speed constant. The net effect of the Krebs mod is ideally to reduce the number and frequency of servo corrections.)