Fun Fact: Endurance riders can tell you anything you need to know about tack that works for the long haul.
You can pretty much guarantee that before we buy it, we've researched it, borrowed it, and tested it for miles. We're a generous bunch and most riders I've encountered are willing to lend gear for you to try. One of the people I trained with let me borrow her $200+ Supracor pad when I was having saddle fit issues.
Honestly, that's often. Dancer - and most equine athletes - fluctuates a lot depending on the season, so I'm always looking for pads to help counter those changes. Obviously, they're not a substitute for saddle fitting, but they help.
My latest purchase is a black Coolback Dressage Pad, which I adore. I got mine from Riding Warehouse, and their version is a little more contoured to fit horsey backs better. I've used a lot of pads, but with this purchase, I was looking for a few specific things:
A super-cushy pad that still fit well under my saddle.
Wicking properties to keep Dancer's back from getting too hot.
Lots of compression to compensate for some of the not-so-flawless fitting parts of my saddle, since I can't afford a full fitting.
Something that stands up to serious abuse.
Easy to clean!
I've been really impressed so far. My first ride in it was the Moonlight Madness 50 Mile in Vermont. The pad never got soggy and when I tested her back the next day (which is when her reactions usually turn up), there wasn't a hint of soreness. I've also shown in it by putting my white dressage square pad under it and using the Coolback on top. Washing it is incredibly easy, too; I just toss it in the washer and fluff it up with this brush once it's dry.
My only con is that if I don't adjust it perfectly, it can be almost too short in the back. I like to pull my pads up in the pommel for tons of wither clearance, and I have to double check that it hasn't been pulled under the cantle too far. That, and I wish it came in pink!