There's a tremendous amount of bad information being thrown about on here in the last few posts.
First of all, sizing is based on height, shin length, and skate size. Without knowing those 3 measurements, it is frankly impossible to determine what size pad they should be in. Saying "I'm in ____" is absolutely worthless. Height is not an accurate comparison either, because people who are the same height can have different shin and leg lengths. I, for eaxmple, have short shins and long thighs for my height. I need a shorter pad with a longer thigh rise to fit correctly. In Brian's, I should be a 33+1" based on my height, but I'm actually a 32+2" based on my ATK. Different pad brands have different measurements as well. Get the measurements, and find the sizing guide for the brand you want. That's the only way of more accurately determining what size pad you need, outside of trying pairs on. And even trying them on isn't perfect unless you are wearing your skates and pants, and preferably on ice because "carpet flys" aren't the same as on ice.
Second, there is confusion between a "stiff" pad and a "stiff core" pad. The stiffness of the foam inside the pad is what determines how far your rebounds will go. This is different from a "stiff" pad, like a Subzero or 1S, which refers to flexibility in the knee breaks. You can have a more flexible pad that still has a stiff core and gives hard rebounds, like a Gnetik and the upcoming 1X. The stiffness of the breaks provide lateral and torsional stability, which helps increase efficiency of lateral movements. However to really benefit from the stiffer pad, you need to have good butterfly technique, particularly in weight transfer and hip movements. If you don't move from side to side with pushes on the ice and recoveries, the stiffer breaks aren't going to benefit you and may actually hamper you because the pad will not twist to be a little more forgiving. A stiff pad will also put more strain on your hips, knees, and ankles. Stiffening the core may help sliding efficiency because the core will better distribute your weight, reducing friction. For me, a stiff core pad with soft breaks is the best. It gives me the torsional rigitity and stability I want, while still providing a little give. A 4-4-3/2 Sub3 or the 1X might be my best options. Vaughn tends to use a softer foam in their core, as do most mid-level pads. That is why they give soft rebounds. The foam used in even the senior level Brian's or Bauer pads isn't the same as what is in the pro models. They are still probably the best values on the market, either the G3 senior or Brian's sr version, because they still have many of the high-end features, and the foam is still pretty solid.
In terms of innovation in pads, no one is innovating like Bauer. End of story. They have used new materials in the 1S pads, and have made a true bindingless pad. Smart straps and post wedges are great. But Bauer has fused an ultra durable and high performance foam to carbon fiber plates and put that into their pads. That reduces weight and thickness. Then they covered that in a skin without bindings. Bindings create friction, and reduce sliding. I love my Brian's. The G3's look very interesting to me. I truly appreciate all of the little features they have designed into their pads. But the 1S pad is leaps and bounds ahead of anything else. Even the little design features are well done. Their version of the smart strap is the best combination of the Brian's and Warrior version. It's wider and more secure, like the Warrior, but still has give because it's made of neoprene, unlike the Warrior. The plastic plates on the knee and calf wings create a great seal and sliding. You can knock the graphics, and glued on decals, and wrinkles. We don't have a good marker for durability yet. BUt they are definitely the most innovative pads out there.
Sizing is incredibly important, even if you have good knee pads. The pad is designed to distribute weight across the knee and calf, which reduces friction and pressure on the ice. That is where all of your sliding comes from. If you aren't landing in the middle of the landing gear, you will be localizing the pressure instead of dispersing it. That limits slide and causes the pad to bend laterally. That landing gear isn't there for cushioning. It's the most important structural component of the pad when it comes to functionality and performance. If you aren't concerned with maximum sliding ability, then you should be getting a softer break pad that will be more forgiving. A gnetik2 is a pretty good mix of the two since it still has a solid foam core like the Subzero. They just design knee breaks into the foam core to allow it to twist. It appears like Bauer is doing this with the 1X as well.