full speed, half speed, warp speed ... none are real world turntable issues ... the real trick to reducing vinyl "noise" obviously starts at it's source; album cleaning & precise cart setup, however, IME, the turntable itself represents the biggest key in limiting noise (it is extremely difficult to design turntables without introducing noise, at any cost).
I've found that the quieter the turntable becomes in operation, the more resolving it becomes, but ... often exposing other issues related to your system, and especially quality of the LP itself. This is why, often on demonstration, better turntables appear to sound less appealing to many listeners, even very experienced listeners ... when compared to lesser (noisier) tables which tend to "hide" other issues while often providing more apparent bass. In my travels, more often than not, on initial listen, the listener often prefers the noisier 'table on first demonstration.
Better (less induced noise) turntables effectively attenuate vinyl noise to a large degree, but what's really happening is that they don't further amp&modulate noise further into the mix. Turntable noise comes in many forms ... but generally ... the quieter 'tables provide a change in sonic perception, a change in sonic character, in that (again, generally speaking) Bass seemingly becomes less apparent overall, compared to a turntable with more introduced internal noise. (I've done this test on the same turntable many times over) In actuality, the perception of more bass is a false positive ... accurate bass starts & stops much faster with greater (and more realistic) initial impact, but appears less "there" overall.
Dallas Justice has repeated stated that he considers Bass reproduction a major problem with many turntables (and esp tonearms), which is true ... but it's certainly not a blanket statement born of any realistic truth ... the real truth is based on his particular turntable/arm of choice, his setup (issues obvious to me when viewing the text & pictures he provided on his wbf posting concerning the very subject matter at hand).
sidebar...
Strangely enough, the near exact same effect occurs but to a lesser degree (more perceived bass) with the addition of more solder-joints, pots, connections, switches, wires added to a pre-amp section. I can still remember, after a relatively recent pre-amp mod (changed the passive "direct" path of electronics) I immediately noticed seemingly less bass ... when testing on a friend who is very experienced with my system (without any knowledge of any mod) ... his first reaction to the session was "where did the Bass go?".
I found his reaction particularly interesting because it mirrored mine on first impression ...
It's as if a very-very-very mild form of compression is added with every passive part (joints, wires, pots, and switches) added to the circuit. As such, my experience when adding even minor (software based) compression to the mix has always provided me with a greater illusion of added, but less accurate Bass. Like listening to typical compressed re-master compared to the much higher DR original (w/CD or Vinyl), greater bass is near always realized with added compression ... a false illusion that many people seem to prefer.
Now, to make matters even more interesting ... I have a direct switch on the pre-amp, so comparison is dead quick and easy. But it's near impossible to hear anything "different" manipulating the switch/test in this fashion; neither I or anyone else (blind) seems to hear any consistent difference when the test is approached in this fast "switching" blind manner. However, extended listening with the switch in either mode for a much longer period of time (a few songs at a time) provides far greater accuracy (when the listener is asked to blindly identify which switch position).
phew ... I digress ...
ps: Martin Barre was awesome live ... this dude rocks Tull.