Actually, it's an exhibition, not a contest of speed. My three Vibroplex No. 4 or Blue Racer bugs of varying vintage:
L. to R, pre WW II, with a U-damper and "cloverleaf" frame; 1946, with scaled-down "Original" style upperworks; a 2001 "Millennium Bug" with full-scale mechanicals on a small base.
From the front, the frame differences are clear:
The damper variations show in the rear view:The oldest one had obviously been dropped and was green and nasty with corrosion when purchased. I replaced the thumbpiece and straightened the frame gently, enough so it would function. The reed (flat spring) had been deeply filed by a prior owner, an old trick to slow 'em down:
The very oldest ones had smooth blue-enamelled bases, probably with the gold-pinstriping treatment; my oldest probably dates from 1921 through '41 but without the nameplate (long gone), I don't think it can be narrowed down any more than that.
They all work pretty well. The 2001 bug has a "bug tamer" extension on the pendulum to slow it down. I'd like to add a "Vari-Speed" to the '46 De Luxe (sold here, scroll down for a video link of the gadget in action), and give that a try. The oldest one, with the filed reed and massive pendulum weight, is already just about right.