What is this blu-spec CD format compatible with s

I was looking around at CDJAPAN and spotted some CD's that are listed "blu-spec CD format (compatible with standard CD players)" What new format is it? Not a format I have seen before and they say compatible with standard CD. So what have we got here and is it even worth considering? Or should I just order the regular CD's.
Do a search It is covered a few times
Ok, better understanding of what they are. But are they really any better than a standard CD? If so how much? Seen a series coming out by one artist that I would not mind having. Just have to justify the extra over the regular CD. And I do not have the special player so do you gain any extra? Or I just run through the blu ray player?

Mostly I just take and rip to my Mac and then run through the D/A converter so what do I gain?
i've toped 50 titles so far...no disappointments to speak of. some have 'runs as small as 1200 pc....all are limited.

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.
BTW: There are a few reasonably priced Blu-spec sample sets that contain 2 CDs; same songs on both discs, one Blu-spec, one non Blu-spec. These sets will give you a very good idea what Blu-spec brings to the table. You could then judge for yourself whether you want to to put out the extra funds for Blu-spec discs. I believe these sample sets are available in rock, jazz and classical flavors.