The other cars you mention may well be over servod as well giving the impression they have mighty stoppers but would probably last 2 laps on track.
This! Most modern cars have a huge initial over-servo effect on very light brake applications. Aka. breathe on the brake pedal and your head goes through the windscreen.
However.. Physics still apply and I find that after this initial excessive 'bite' they tend to be fairly mediocre when it comes to full braking (not much extra happening after this even when pressing harder) and wooden/lifeless pedal feel. Not to mention that they fade badly after some repeated stops.
Nice case in point.. This video...
AMG E-type with massive brakes, but notice how after not even a single lap Frank already mentions that the brakes seem to be fading and Lewis confirms..
Not to mention most cars these days also have some form of EBA (emergeny brake assist) which kicks in when you exeed a certain speed at which the pedal is depressed giving an extra 'head snap' feeling.
This is all done on regular cars because data logs from crashed cars have shown that most drivers never reach more that 70-80% pedal pressure even in an emergency. (with loads of people actually scared of the vibrating brake pedal when ABS kicks in and letting off as a result..)
IMHO the VX/Speedster is nicely setup (as is my old Pug 107 ). I still prefer my un-assisted Elise, but the amount of assist on the VX/Speedster is pretty spot-on. Don't want it to be too 'grabby' as the lack of weight on the front axle means you can lock up the fronts if the 'grab' is too agressive. Need a little time for the weight transfer to load up the front and allow you to progressively ramp up the pedal pressure.
The lack of 'dive' on the VX compared to front-engined cars also makes it feel a lot less dramatic and it seems like you are not slowing down as much, but when you do some repeated brake runs on a test track you find out these little cars are often easily the ones that consistently have the same brake distance the 1st and 10th time.
The 'softer' initial bite on the VX is IMHO a pro, not a con as it allows you to lean into the braking without upsetting the car immediately.