So I think my saddle search has come to an end. I got my mare fitted on Saturday and my Cactus CJ James actually fits her pretty well, BUT it has a tiny bit of rock(I'm talking it moves maybe a fourth of an inch or less when you apply pressure) when it's on her back which is making her sore. I really don't want to get another saddle because it does fit her well overall. I currently ride her in a 1" 3000 Series Wade which has 3 layers of air gel and memory foam in it and she still gets sore in the middle of her back. I personally think it is too dense for what she needs. 

So now that my saddle fits her.. I want to find a good saddle pad to combat the rock and help relieve some of that pressure. I've been staring down Saddleright as there are a ton of reviews out there that says it pad will help with this, but I'm stuck between the standard and a legacy.. and they are expensive. The only thing that is nice is they have a 30-day return policy, no questions asked so if it doesn't work.. I can return it and get my money back or switch it out. I have also been thinking about a CSI pad. which are equally expensive. 

Does anyone have any experience with this?

Ohh I don't know but I would consider getting a 5 star and shims if you want to keep using that saddle. I've had both Saddleright and csi pinch rub and sore horses. Ugh. It's such a battle sometimes. 
csi also sells shims so you could try that, they also have a 30 day guarantee. 
Saddleright only worked for me if the saddle fit perfectly. Even then I felt like they were hot and didn't keep it. 

CSI with some shims. 

When you guys say Shims, can you elaborate? I had a custom swayback pad made where it was 3/4 and 1 1/2" in the middle and it made the rock worse. So when you say Shims, where would I shim? 

shim the front usually, maybe the front and back. depends on whats going on

Yes, I think a sway back pad would definitly make rock worse, you are lifting the middle of the saddle basically and if the saddle fits except for the rock then it would IMO create more rock.

Sounds more like you need one with a tiny build up in front and back to fill in the area of the "rock"??? I'm no expert by any means...

Thank you! This makes sense, I will have to look into this! 

Again, no expert but just seems like that would be the case, like wearing a shoe that only touched the gorund in the middle of our foot, toe and heel were off the ground and then we padded the middle of the sole of the shoe creating even more rock...

So I have an update.  

Saddle actually fits. Saw the Vet last Wednesday,  did Xrays. Her hocks are fusing, which is where the soreness is coming from. Hock injections were done to make her more comfy.

Sorry for wasting your guys time! At least I know what the issue is!

I'm confused...injecting her hocks solved the saddle rocking?

I'm confused too, was wondering the same thing

No, I thought the saddle was causing the soreness. It is not. I had an extensive vet check done including with a chiro who was also a vet, and they both concluded her back soreness was not from the saddle but in fact, her hocks that are currently fusing. It has all been very confusing to me trying to figure out what the problem is. The saddle is not the issue after all.