I have used this capo for many years and I am still using it. I have recently discovered the G7th and do think they are much better than the 'trigger' design of these Dunlop Capos. But then they also cost twice as much.
What I like most about the Dunlop capos is that they are pretty lightweight, sturdy and don't really cost a lot. If you compare it to models by Kyser I think that Dunlop has put a lot more thought into their design. Kyser are of very good quality as well - but they are quite big and the spring is pretty heavy. This doesn't allow for quick installation as strings often get out of tune when so much pressure is applied.
The Dunlop capo has in my opinion just enough pressure to ensure a good sound while keeping the pressure on the neck closer to what an actual guitarist would achieve with his hand.

As for capos please don't invest in a cheap one - especially when you play steelstring guitars. They simply won't last and you will never be able to get a good sound. These Trigger Capos are not much more expensive but are definitely of much better quality.
As I said - I prefer the G7th but would never give this capo away.