RB, You wrote, "Direct drive tables tend to have worse flutter than belt drive, because direct drive uses impulses to rotate the platter while elastic belts tend to absorb vibration from higher speed motors."
First, is the premise correct? Do DD TTs in fact have higher flutter than belt drive? I don’t know one way or the other. But to your following point about DD TTs using "impulses" to rotate the platter. This sounds like the old "cogging" allegation that BD lovers foist on to DD TTs. The treatment of cogging is either to use a lot of poles, so the impulses are very closely spaced, and there are other tricks of the trade that address the timing, all of which are very effective in rendering cogging inaudible. Modern or even late 20th century DD TTs don’t have audible cogging. Plus many of the best DD TTs use coreless motors that are inherently free of cogging. As to the bit about the belt absorbing motor irregularities in a BD TT, that depends entirely on the compliance of the belt, and that speaks to one of the most common points of discussion with BD. Should you have a noncompliant belt so the motor can control the platter as stiffly as possible (but this allows noise transfer) or a compliant belt that isolates motor and platter, relatively speaking, but allows stylus drag and any other sources of friction to slow the platter before the motor can compensate, even assuming the motor is seeing some sort of feedback vis platter speed? With a compliant belt the platter speed can vary up and down, as the motor tries to catch up with what the platter is doing. Like "cogging" with DD, the issue with belt compliance and motor torque in BD TTs is more for argument's sake than it is a major determinant of SQ, assuming well designed and built examples of each type. But there is no free lunch.