Blu-spec and Blu-Ray are two different things. Blu-spec can only be played on regular old CD players. Blu-Ray discs require a Blu-Ray player. Blu-Ray discs also cost much more than Blu-spec CDs. And, there are very few titles available on Blu-Ray disc.
Blu-spec CDs I have heard sound very good. I have never heard a Blu-Ray disc and it's very possible that I never will.