Profile is most well known in the BMX world, and mostly for their hubs and cranks. They also make hubs for big-wheel bikes. Enter the Elite MTB hubs. Made in Florida, available in several colors, and all axle standards, with a Shimano or XD freehub body. The Shimano freehub's are 11spd road compatible even. Weight wise they're a bit heavier than Chris Kings, by about 30g or so (depending on the axle type). They're also a bit more expensive, going for about $50 more than the Kings for a set.
The big draw is the freehub mechanism. They use a pawl system, with six pawls arranged in three offset pairs, so two engage at a time. Paired with the 68T drive ring, you get a whooping 204 points of engagement!! More than Chris King (72) and even Industry Nine (120). Stomp the pedals, and the engagement is instant, power is on immediately.
They make a TON of noise when coasting. Seriously, they're loud. Roll up to a group ride and people go "Dude, WTF?!" kinda loud. King, I9, and Hope all sound like a whisper by comparision. Personally, but YMMV. You will not sneak up on anyone. It's funny how quickly you (and your riding buddies) get used to the noise, it's really a non-issue IMO.
The freehub body pulls off by hand for easy cleaning. You do need a rubberband or something similar to collapse the pawls to reinstall the freehub body.
I had a chance to ride a set for a bit, and I'm sold. Whenever I get around to lacing up a set of dedicated SS wheels, these are the hubs I'll be using. The drag when coasting is on par with King and should improve with miles. I9 is still has the least drag of all the fast engagement hubs.
If you want the fastest of fast engagement, look no further.