What I mean by true sync speed is what everybody understands as a sync speed, that is the entire sensor is unshaded by the shutter curtains for the full duration of the flash exposure, we all understand the black bar we get with focal plane shutters, what nobody espousing the vast superiority of leaf shutters seems to grasp is how they actually work. They open and close and it can take a surprisingly long time for them to do it. They do not expose the frame equally, it just appears that way because the shutter acts as a second aperture, this costs flash power and increases you flash illuminated dof.
Look at these videos and you will understand why the leaf shutter pundits are barking up the wrong tree.
http://www.khousen.com/blog/files/Fuji%20X100s%20Shutter%20Speed.html
The only way to get "true" high speed sync is with electronic shutters.
As for the links, as I said earlier, the power output has a huge effect on the T1 and T5 times, the Einstein does so well because it has the same circuitry as our hot shoe strobes, IGBT cut off controllers. But those 1/13,000 exposure times are a 2.5Ws, nine stops down from full power! The $14,000 Profoto set puts out a mighty 4.5Ws....... If you can light something with 2.5Ws you could be using a $50 285 clone, if you needed 5Ws you could do it with two!
Of course that is a little tongue in cheek, but I just wish people who made silly comments believing in a technology that clearly don't understand it would lighten up.
As for the wonderful liquid images that seem to be the area most often needing very fast flash times, they are not relying on high sync speeds as much as short duration light pops, after all they lower the ambient to not become a factor in the exposure.
The people that need high speed sync are the ones trying to overcome uncontrollable ambient, but again this is often a diversion, after all once you go above sync and min iso you have to increase dof, and that is often not the desired payoff. So you need to use ND filters to control dof and these can control sync speed too.
As I said, one stop of sync speed is very workable, 1/250 for a focal plane shutter at 50 iso is just the same as your expensive leaf shutter equipped lens at 1/500 sync and 100 iso, you'd have to be crazy to pay any money for that non difference.