What is the advantage to the speed or
trigger clamp?

One of the benefits of this one is that on here, on the fixed end, you have a little butterfly nut, you can actually reverse this, put it on the other end of the clamp, put the screw back in – and now, if you wish to glue something and spread it out, (imagine a door frame with one of the larger clamps. It could be a cat-flap, it could be a rabbit hutch, bird box). What you can now do is actually use this to actually spread out and hold something whilst it glues or while you need to drill through it. Multi-purpose, very useful.