First, read up on an explaination of t1 vs. t5 times:
For most strobes, the t5 time (the one that "matters") shortens as your power increases. because the 1600 is more powerful, it has longer flash durations all around. To sync a flash with your camera so that the shot is actually lit up by the flash, you have to shoot at slower shutter speeds. Therefore, the flash duration becomes your effective shutter speed, and so a short t5 time is needed to freeze action.
However, if you shoot full power it's still 1/800 of a second, which is enough to freeze most action, especially if you track your subject with your camera. And, like I said, with the new PW you can sync a lot faster anyways, so you won't outgrow your lights for a long time.
So yea, they are slow. That likely won't be a limit to what you can do with them for a long time to come, so long as you understand the limitations and how to work around them.
But, if you aren't trying to light people up during the day, you don't need that much power, and it might make more sense for you to get the B800 as it will be easier to use.