Well, it seems like everyone here who has replied has never done or shown western dressage, so I thought it might be nice to add the opinion of someone whose main discipline is western dressage.
First of all, I think it's very different from other western disciplines, which I saw I lot of people saying that it wasn't. I've riding in almost all different western disciplines, and I can surely say western dressage is very different.
Also, my trainer was one of the co-founders of the discipline, so I guess I have more help and exposure to how western dressage SHOULD be done, than how some people are choosing to do it.
I don't know where all of this stuff about over-doing contact and what not came from, but I've never seen that at shows I've been to. Of course, I show western dressage at Breed A shows, so there might be a lot more experienced people there who know what they're doing. I school my horse in a snaffle, and even warm him up in one before the show. You collect them just the same as you do in a western pleasure class (Morgan, not QH-- their head carriage should look like this
, not peanut-pushing. There should be some contact because it's dressage, and that's how dressage is. It's not western pleasure, but you do have to be careful with a curb bit, just like english dressage riders have to be careful with a double bridle.
I feel as though Western Dressage, at the least, provides a very good foundation to other western disciplines, just like english dressage is a great suppliment to other english disciplines. It teaches great horsemanship, and really help you and your horse become balanced and in-tune. I read one of the replies that said that the western dressage tests were easy, but JJ's doing pirouettes at the canter and starting piaffes, so I would say to hold your tongue on that one :) Also, it's a very new and developing discipline! Give it some time to build up a foundation and standards. As it grows in popularity, more difficult tests will be made, and people will start to become more involved. So far, I think that western dressage has done wonders for my horse and I that any other western discipline could have NEVER done, and really, is no less supplimental or beneficial than english dressage is to english riders. It really does teach the grace and standards of english dressage except it has been adapted to western riders, which shouldn't be under appreciated.