I do. I got it because I only have one mountain bike and my riding tends to be either short play-orientated blats around with mates or long events or SDW rides, and clearly the range of positions one might want is quite variable.
A few observations:
They are surprisingly light. They probably don’t please all-out weight-weenies, but there is certainly not a notable weight problem.
They adjust easily and quickly without fuss. It is a clever system.
The range of adjustment is surprisingly large, it makes a real difference.
They feel entirely secure, no concerns about their strength, and they do not creak.
They look vile.
🙂