There are SO many bullshit claims by kite companies regarding light wind capabilities. NO kite will perform in < 7-8 knots. The owners and distributors of the Epic Infinity are amongst the worst offenders. To claim the Epic Infinity can perform in "2-4 knots" (even if it is with a SUP) is ridiculous and a blatant lie and leaves the company wide open to claims from disgruntled users.
Continually posting videos or images of kites flying in glassy or conditions without whitecaps makes me think the posters are trying to hide something or deliberately trying to mislead. Anyone with any significant light-wind kitesurfing experience knows there must be significant wind gradient involved.
The ONLY way to gauge the RELATIVE performance of kites in light winds is to fly them side-by-side, with similarly experienced riders and similar boards.
With BIG light wind kites, there is no magic formula. Various permutations and combinations have been tested over the years: If you want a fast turning big kite, it needs to be fat (meaning long middle struts), but the payoff is less upwind ability and slightly inferior low-end due to the lower aspect ratio. If you want a kite to go upwind better, we know narrower kites (higher aspect ratio) work better, but they tend to turn more slowly. Flysurfer's "Speeds" are very narrow, but very SLOW turning due to the wing tips being so far away from each other and the inertia of pocketed air. There is no such thing as a fast turning, ultra-low end, exceptional upwind, easily relaunchable kite with a lot of range. There's always a trade-off.
It is simply not possible for the Epic Infinity (V1, 2, or 3) or Flysurfer kites to surpass significantly the performance of every other light wind kite in existence. There is not enough energy for ANY kite to perform in 2-4 knots of wind!
The Epic V2 Infinity has been tested alongside other light wind kites (e.g. North Dyno 18m) and has been found to be wanting at the low end. Objective testing of previous iterations of the "Infinity" showed it was inferior to other kites in very light winds, despite Epic's propaganda: http://www.thekiteboarder.com/2011/05/e
Epic's owners were patently misleading re the V1. They should not be believed about more recent iterations.
A light-wind showdown" amongst the biggest claimers (Flysurfer, Epic) and others (North, Core, Slingshot, etc) would be one way to clear this up once and for all.
Of course, there is a simple way to put to rest ridiculous claims by Epic or any other kite company: BUY THEIR KITES. If they don't perform in objectively measured 2-4 knots on a SUP or whatever - let alone below 7-8 knots (and they won't), then return them. The tsunami of returning light wind kites will force these companies to be more truthful with their advertising.
Ignore the lies. Ignore the propaganda. No kite can perform under 7-8 knots, let alone 2-4 knots.
If you have the chance to test it, go and have a ride with the Infinity. That would be simpler.