We have one and it's lovely and comfy to ride in, and I think pony agrees from his point of view. Have had to change the gullet once as he has changed shape (less fat more muscle), so is definitely good from that aspect. Handily it also fits our other pony on the current setting.
I have one for my cob (just the normal GP model) and I love it - very secure for jumping, hunting, etc ... I've even taken it out to dressage on a horse that wouldn't fit any of my dressage saddles. Looked a bit out of place, but didn't make me work too hard,.
I bought one for my VERY difficult to fit 20 yr old Section D, in 11 years none of the saddles fitted to her have actually really fitted and this time i wasn't going to settle for something that i wasn't completely happy with being told this is the best fit unless you want to get one made. So my saddler reccommended trying a Kent & Masters but it would need to be brand new as there just aren't any second hand ones... and well... it fits like a glove, it's perfect for her! it is so comfy to ride in, she seems to have a new lease of life when ridden now,to the point that she actually enjoys being schooled so she is clearly so much happier in her new saddle... which makes me very happy and think it was well worth the money! Highly reccommended
Not quite the same but my daughter recently bought the K&M Jump for her TB gelding and she really rates it, says it feels like a good quality saddle and I was watching them work on the flat the other day and have to say he really did look a lot happier, but obviously that's not quite the same model as you are asking about