I am also not nit picking, but we are talking Apples and Oranges. I am comparing the Infinity ULTRA vs the ARC Limited Edition (or L.E). Your reviews are comparing the old Infinity Task Light vs the standard ARC, which I will agree is a better light than the old Infinity. The Infinity ULTRA, I believe, is shown to match the ARC L.E. in brightness for around half the price if you shop around. (Best price I have found is Texas Tactical Supply) It does come down to confidence in the product and personal preference. So Whichever you prefer is the right choice for you.

Turk