I would say the AI tops out at 10mph, but much more realistic average speed is around 5-7mph. At least in rolling 3-4 foot waves in about 15-20mph wind in hawaii, that's what you can expect.
I would get the hobie trax 2 with the latest balloon wheels. They work pretty well on sand and would probably be fine for paved as well. They are also stainless steel so less corrosion. I bought some used off brands for $60, they worked ok, but rusted out and needed repair after a year. I then bought the trax2 for $200 and they work great and I get the feeling they will last a long time!
It's a fun boat with little maintenance cost, so far

, and you can launch it from so many more places! It can really rip in the right conditions as well! Oh get some goggles if you like speed and have any sort of swell, it helps you see thru the buckets of water thrown in your face, haha!