The higher level blade you go, the harder it is to find the sweet spot for a spin. The larger a toe pick you go, the more apt you are to "scratch" when going backwards. Yes, it is easier to skate backwards if you are scratching (because you have two points of contact on the ice). But, it will drive the coaches/judges nuts because it is so technically incorrect. And, it's really ugly to watch someone constantly on their toe pick, going backwards, and scratching. To keep from scratching, you are going to have to learn absolutely correct posture (bending knees deeply).
I just went from a lower heeled Harlick with MK Professionals to a higher heeled Edea with Jackson Ultima Elites. These changes put me more forward on the blade. I could easily do 15-20 revolution forward spins and 5-6 revolution back spins, multiple combinations both before and after. But, I had to watch it on skating backwards, because I'd scratch in the higher end blades. Jump landings, scratch. It took a few months to get the jump landings without scratching. Now, I will consistently scratch sometimes on backwards power pulls in certain areas of the curve. If I scratch, I have to bend my knees more. At first, I was trying to bend from the waist, which totally screwed up my loop jumps (and all jumps). But, my backwards figure eights (both backwards inside and backwards outside) are not scratching. (I have been practicing them since October, when I realized I was scratching so much going backwards) All spins are back, but my camel has been a mess. My rotations on the camel spins are still too big of a loop, but are getting smaller. (My Moves in the Field video has a camel at the end). At least now, I don't fall out of the spin. Again, higher level blades might take you down a notch in spinning, especially on a harder spin. But, my layback is now easier to do!
The MK Professionals are a standard teaching blade. They have a two point curve system, and a big sweet spot. They are a little flatter, which helps in spinning. There is a also larger bottom & top toe pick, which does help tremendously in learning fast forward and backwards scratch spins, and toe jumps.