I have one. I didn't run any of the other blocks first, so I have no basis for comparison BUT what makes it worth that much IMO is the quality. It has no metal parts. It's all snap together, so if shit falls into your engine, it's just going to be the carbon reeds and not anything that could fuck up your engine.
Performance-wise my Gila is pretty beasty but I couldn't say what % performance increase I saw.
Hope that helps.