As far as speed and fluidity (as well as features) are concerned, Surface RT is a class of its own, Android and iPad tablets can't even compare. Seriously, look at the videos; it'll blow your mind.
You know, i'd sooner trust a review written by someone who has used one extensively over a video where it simply looks smooth.
Besides, all that was shown in the videos you linked and the videos posted in these threads before are of simple UI interactions and base applications like browser/weather/stocks/pictures. Nothing remotely resource intensive and hardly "mindblowing", as you call it. Still it is very smooth, but apparently it does not hold up under actual real-life day-to-day use.