I know a few pikers with the Guideline, they prefer it as you sit on, not in the water, and being that bit higher, double hauls etc. don't end up with a wet left arm.
HOWEVER, they also say in a wind, they are hard to control as your body is not acting like a droge below the water and that when you need to kick hard, your feet are a tittle high in the water so you do not get the same power as a more conventional tube.
The only thing I would say about the Vision/Ron Thompson is that it only has two proper bladders (I would not count the seat one as a floataion bladder as its small) and if you are venturing out on certain highland lochs with Captain Von Hamish of Das Boat fame, I would be a little uncomfortable.
But then again, you can walk on water when it comes to casting so why not forget the tube and just do a Jesus?