I posted an article about a working Jet bike back on my facebook wall some time ago. Yes, it was on IGN lol.

Now the article in the above link says that the bikes have been tested at speeds of around 30mph that's 26.07 knots. It also states that one of the jet bikes can fly at speeds comparable to a helicopter. So I did a bit of quick Googling...

Quote Originally Posted by Yahoo Answers
Without diving into a lesson on helicopter aerodynamics (eeek!!!!), let's just say that there are a number of factors that limit the speed of any helicopter and various ingenious inventions have appeared to try and overcome them.

With the technological advances we have seen over the last 25 years, it's fair to say that the average, modern-day helicopter will probably cruise somewhere between 120 knots (222kph / 138mph) and 140 knots (260kph / 161mph).

However, the fastest helicopter remains the Westland Lynx . . . which set the helicopter speed record on 11th Aug 1986 (yeah - 21 years ago!!) It flew at a speed of 216 knots (400.87kph / 249.1mph) in level flight - something that has still not been beaten.

Here's my Lynx flying video - enjoy! Blue Eagle Westland Lynx @ Red Bull Air Race, London, Jul 07 - YouTube
Source(s):
I'm a Lynx Pilot!
I'd say that's pretty spectacularly accurate since the guy posted sources and is claiming he flies them for a living. Now, he's saying the average helicopter flies at around 120 knots (138 MPH) - 140 knots (161 MPH) so essentially one of these jetbikes in my link would be capable of flight at these speeds. Now consider ease of steering, comfort involved and the fact that whilst the speed may be lower than that of a rocket pack if you were to accelerate from 10000ft - ground level that we are talking about a VTOL bike what doesn't require a parachute for a safe landing or a plane to get it up to height. If we're talking the sort of Jetpack a-la James Bond or Kick Ass then we're talking about a VTOL unit which would not maintain a high speed for long due to the lack of fuel it would carry and also the restrictions of the human body.

Therefore if we factor re-fuelling stops and distance travelled in to the equation I would definitely argue that my jet bike has a far superior speed and range to your jet packs.