Some of my favorite times dancing have been on pure MDMA! Yes, setting and other factors (dosage, purple clowns, etc.) can affect your ability to dance. Not to mention, 'dancing' could be anything from articulately grooving to music, to pounding the hell out of the dance floor, so requirements vary.
When I want to roll -and- dance hard for long periods, I take speed (meth!) once the roll develops nicely. This also helps me with the E comedown.
In the end, I find the best, assured dance recipe to be MDMA + crystal/powder speed.
Taking just speed can be great for dancing too, but I dance best with the energy of speed combined with the lucidity of MDMA.
'Speed bombs' are almost never strong enough to keep me going.
Speed bombs aren't a very economical choice.