Since you would be right at the source of the sonic boom, it would crack your bones and liquify your organs, but that's only if you could withstand the force of 700+MPH winds and the backpack pushing you into them... probably also crushing and breaking your back. The jetpack would also set your ass on fire. There is a type of mini-jet airplane technology (acro jet?) that's been around for decades that could probably be upgraded, but those aren't VTOL.
On a more serious note, a dozen or so years ago I took some interest into newer micro jet engine technology (used in very large RC models) to see how practical it would be to make a jetpack. I really hate traffic around here. It takes forever to get anywhere. I figured I probably could get airborne with a pair of jet engines, but they would guzzle about a gallon a minute of fuel, so that turned out to be impractical. A year or so later I noted that some engineer did make something like this with better fuel efficiency, but the time and range was still extremely limited. I haven't looked into anything recent.
There is a type of water thruster made from jetskii technology that can get you up in the air. It's also not very fuel efficient.
I don't think anyone's combined water skiis and that working jetpack I mentioned. Since the jetpack wouldn't be fully lifting you in the air, the range could be much further... but then again, to quickly cross a narrow body of water, a regular jetskii would be cheaper, more efficient, and safer. If you did set your ass on fire with this combo, you could just drop down into the water, but jet engines wouldn't go for that and you'd probably sink under their weight and drown.
I don't think anyone's combined a hang glider with micro jet engines. If you get that working and wear your Sonic suit, you're likely to get shot by rednecks here in Texas. We don't take kindly to the flying rodent apocalypse.
I'd really like to get electrogravitics working. Then I could make a small UFO to avoid traffic and freak people out at the same time. If it's small enough, it could fit in a standard parking space.