I love mine - it gives you a great level of control and I use it for lunging and long reining too. It's a good tool to have in the general horsey box.
It's great for schooling when loading, as with the old pressure and release on the nose it allows you to keep their feet moving, either forwards or backwards, so they can't plant themselves. If you get one, just remember not to tie up off the nose loops, but from the normal headcollar loop under the chin.
To be fair, with young un's I always find feeding them in trailers, then walking them through without actually taking them anywhere for a few weeks in advance of travelling them, works a treat and negates any loading issues.
Welshmonsters, all of our welsh monsters are in them as a matter of course, as I think its great that they are normal headcollars you can tie up in when not on the dually setting, but give you that bit extra when you need it. You do need to spend the time schooling to it at the beginning though, don't miss that step
Our 14.3 is in a red one and the 15.2 in a black one, so depends what size bridle he wears I think - ours are cob and full. Hope that helps
You need to learn how to use them properly though. They come with a DVD that you need to watch, and it's worth getting an RA out for a session if you need to sort out a particular problem.