They are large comfortable jugs. That's a fact. But could they be used as a roof hold? My answer is yes for an intermediate to advanced climber. They might be a little too hard in a roof for a beginner climber. Either way, expect a pinch like jug in roof sections and steep walls. They will increase your pinch power with it's jug style design...that is if you can hang on them.
The divot design style is a great way to get a little bit more out of a hold by using the divots as thumb catches. The steeper the wall gets, the thumb catches encourage a slight pinching action on the hold. This allows you to move off of the hold with more hand control and confidence. As always, the are comfortable and functional which is exactly what a climbing wall needs.