well, the reason why I would want a bluetooth solution from the factory is if you can integrate the system into your radio/dash, have the mic built into the car somewhere and hidden. To me, that's the only reason to pay a premium to get a system from Mazda.
This looks like another add-on ones, could even bee made by another company. I mean, it says that it's what, 450 installed? That's like $700 USD right? You can easily get a bluetooth kit for like $100 to $200. If it's not going to be integrated (you know, like Acuras, it's part of their voice commands, steering wheel controls, etc.), I don't think it's worth the extra money.
I've installed a couple of these, even hooked it up to the stereo so that it mutes when a call comes in, etc. Works fairly well, and cheap...less than $200 (free labor of course).