I first learned of Barber pedals like most people probably did, through the Guitar Player review of the Direct Drive. To be honest, I bought one and thought it was ok, but it didn't knock my socks off at the time. I was heavily into Fulltone pedals, which are great too, but in a different way. I really didn't get into Barber until I heard about the LTD SR (Special Recipe), and for reason that escape me now, bought it. I got one of the earliest ones with the LTD Silver box but the green LED. I was sort of weirded out by that, since within a few days of getting mine, the new livery was posted on the Barber website. Regardless, the thing was amazing in that the tone control was a boost/cut design, and the overdrive was very transparent (I agree with the descriptions you see on the Barber site). I went on a buying frenzy, and now own all of the LTD, Direct Drive and Burn Unit/Small Fry variants currently in production. I've also gotten the Launch Pad and Tone Press to round out the collection.
Barber pedals are built to last, have a clear, articulated sound, and suit my ears and gear really well. A unique feature is the tweakability of the pedals. Not only can you switch out the op amps, Barber encourages you to do so, and tells you how. Also, the pedals include various tone shaping controls inside the box, so you can tweak the tone to fit your style. This, along with the basic sound of Barber pedals, is what sold me. Fulltone is great, but has a different sort of sound than Barber. Choose what works for you, since they are both excellent.