having spent a little time flying both of these, all i can say is for the price, wow, what a deal. you get a lot of kite for the money.
maybe they named it infinity because of the amount of potential bridle adjustment.
between the vented and the standard, i think the standard flies a little better, but isn't that the same for all vented kites? here in vegas the wind is up and down, you'll be flying and the wind just drops out. with that in mind, the vented flies in surprisingly low wind, so it's unlikely you'll find the kite just dropping out of the air should the wind fluctuate.
according to the included nomenclature "After only a short acclimatisation, the pilot gets the feeling of being one with the Infinity kite. All known tricks are possible. The sideslides are endless..." i'd tend to agree, one of our local pilots really got along well with this kite and he was performing tricks which previously had been just outside of his capability.
the kite fills the sail nicely and provides good feeback on what the wind doing. to be honest, the frame is a little more flexible than i'd expect but it hasn't proved a problem in the slightest.
to me hq will score big with this one. like the shadow, it's a kite beyond it's own price.