OK, here we go
Quality wise, all three pads I've owned were very well made, high quality materials. No issues there except all three are rather overpriced, although I have not have had any issues re-selling them at a good price. The sheep skin ones are of course much more cosy and comfortable than the felt pad.
As to which is/was the best, it really depends on the intended use and your horses conformation and sensitivity to pressure points.
MY horse couldn't take the use of stirrups at all. Not with the Christ, which has a kind of surcingle going all the way around the horse and putting a bit of pressure on the spine, nor the Grandeur, which is basically two halves with a bit of spinal clearance, even with extra padding.
Personally, I would not recommend the use WITH stirrups on either pad, no matter how much padding you use.
The Christ is the nicest material (being all sheepskin) but also the least padded/solid one. The two others offer more stability.
All pads will make your horses feel quite a bit wider than they would feel with your saddle or even bareback, especially with extra padding. With owning mostly drafts you will most likely end up in a chair seat, or even at a point where your hips just can't take it anymore. (I've had that happen with the Grandeur plus extra padding
).
Also, if you choose a pad with thigh blocks (or any kind of blocks) make sure the whole thing puts you at the right spot on your horse. There is really no room for error. The Blocks will put you in a specific spot in the pad and the position of the girth straps will put the pad in a specific position on your horse. A few inches off and anything more that walk will feel off and bouncy.
MY horses girth area was never really in ballance with the best spot for me to sit on him, so I was always sitting a little further back than would have been ideal.
If there is any chance for you to try the pad a couple of times before buying I would very much recommend that. But like I said, they have a pretty good resale value.
Taking everything above into account, I'm very happy with he one I have right now, the felt pad. It was the best fit for me and my horse. The way the girth straps are attached just to the bottom of the pad makes it almost impossible to put pressure on the spine. No thigh rolls or anything to put me in a forced position. I've had it the longest and it's staying. I love and enjoy riding in it.