The Fusion isn't over hyped as the Solid is underrated. The Fusion is a great blend piece for when the Solid leaves flat corners and the Pearl is still skittish. But the Solid gets more use as it isn't as jumpy yet is still very continuous. I am 19.5 mph off my hand and 450 rpm. So I tend to like solid pieces more so than pearls or most hybrids. The IQ Tour Solid is a must have in the bag as your go to ball. I am on my 4th one, and not because the other 3 "died." But rather, I love the ball so much I have 2 dull and 2 shiny, a pin up and down on each. I can use them on the USBC Team pattern of 43 ft. all the way to Beijing at 35 ft.
To sum up the IQ Tour line:
Solid is your benchmark piece. It reads the mids, yet can still turn the corner with authority. It can handle some heavier oil volumes, especially at 1500 grit.
Fusion is your blend piece. When the Solid reads the mids too hard and you need to move left and open up the lanes a bit. A controlled flip as opposed to the hockey stick the Pearl offers.
Pearl is your late block piece. It is extremely clean and angular. On fresh THS', it may be a little over under. But when you have to get deep and swing the lane, this ball will finish and carry the corners.