ZenmasterDallasThey have "improved internal components" and a slightly upgraded wing design. Also some extra ear tips. Aside from they are pretty much identical to the original. Still Bluetooth Class 2.1+EDR and aptX support. Personally I do see it as much of an upgrade.
I have the original at it was good when it first came out. I'm have recently tried several of the alternatives out there. There are better sounding BT workout headphones, Plantronics BackBeat Fit, Jabra Rox and JLAB Epic Bluetooth to name a couple I recently tried. All offer new Bluetooth version and most have aptX. Not to mention are all less expensive. How they fit you will be a personal matter. I've had them all and settled on the BackBeat Fit as my overall best option (with JBL Endurance tips for great isolation and sound quality). They all sound better than the Bluebuds with superior bass response for less money.
I will say when my left ear bud stopped working I got a replacement from Jaybird in about a week or so after sending them in. That's worth something. SO its a good company from my experience, they just haven't really improved the product to keep up with the competition (better sound quality, BT 4.x, AptX support).
Jaybird still has the recognition from the original, but I think they are too expensive for what they offer.
just something to consider.