I've ridden a couple of models of the Vado and the power application is so astoundingly smooth that you don't even realize it's happening until suddenly you are flying along. The best description I can give is that it's like having a really strong tailwind, you don't -have- to move but if you want to you will. I've never had that "maverick horse" feeling that the bike wants to move on it's own or unpredictably.
I have no idea how they have the torque sensors tuned but it's exactly like riding an analog bike and if you aren't pedaling, no boost. If you are just sort of piddling around (say "idling" in lazy circles in a parking lot) the bike barely pushes enough to even notice and if you mash on the pedals it PUSHES you with no delays and a smooth power curve.
The one think I dislike about my Motan (and cadence sensor style in general) is that on slow lazy turns in a parking lot it still sometimes surprises me with unwanted power if I forget to turn the PAS down or I forget to "ride" the brake lever to override the motor. Even rusty as I am, I'm still skilled enough to cope with it but I'm sure it's thrown some inexperienced riders to the ground and that's no fun even not counting a 70+ lb bike falling on you to boot.
I am strongly of the opinion that cadence style systems are going to go the way of the dodo as ebikes increase in popularity because the torque systems give a lot more latitude to the uninitiated and are more supportive even for the experienced rider. I think the prices for Torque based systems will drop fast (seriously I know how they are built, they are CHEAP to produce so the price markup is just silly).