I'm alsop biased since I'm one of Rob's students
Rob Kahn is incredible, his Jiu-Jitsu is on another level. When I started training with him my game took off, he will make you reach your highest potential. His techniques are very innovative too, you will learn things that you won't see anywhere else, I guarantee it.
Also, I've been to his place in Tampa many times (I live in New York - rob used to teach in Westchester before moving to Florida) and his students are very skilled and helpfull training partners. Some of his purple belts have even defeated black belts in competition.
Rob just made his MMA debut this weekend, he won via armbar after 1 minute 30 seconds (guy wouldn't tap so he had to break it). Rob's top student, Justin Garcia (abu Dahbi veteran) fought on the same card and won via rear naked choke in 40 seconds (put the guy to sleep).
If you want your Jiu-Jitsu to take off then get over to Rob Kahn's
www.Gracie-tampa.com