It sounds like the same debate that we have about every other piece of gear. Does it fit? If it doesn't fit you, it isn't right. Personally, the speedplate have made my skates way more comfortable. I tried superfeet. and they didn't feel right at all, tons of arch pain. That being said, there are lots of people who had the exact opposite experience. It sounds like the speedplates are myaybe not quite as moldable as advertised, and there is a more specific foot type they fit, but for me, they are just right.
I cannot speak to durability, as I have only had them a few months and am a pretty casual player. We shall see how they hold up...