Interesting, I was recently looking at the OCX 686i. Apart from the different design, do all 686 models share the same drivers?

I'm super excited for this, since I thought their old model sounded great. My PMX 685 crapped out on me in 5 months so build quality is a concern, thank god for the 2 year replacement policy, I need to take them up on it.
 
But really I don't think anything will beat the SQ of the KSC 75 in budget exercise headphones, though they too break within a year but have a lifetime warranty.

^ Did have a pair of the PX685i recently and the MX686 is probably not going to be quite as warm as the headband models due to a looser fit. The MX686G was more refined and smooth esp. in the treble, had cleaner airier mids, and less thick bass that showed more detail and wasn't as much of the focus over the mids and treble. PX685 was easier to fit and the silicone headband gave no comfort issues but I was surprised that the 686G gave the better outdoor enjoyment as far as sound. PX685 has the typical sports tuning but since it is grainier and not as smooth it got clearly beat by the new 686. I'm sure the PMX686 will be warmer like the 685 but smoother and more refined. 686G cable is much, much better except for the blue color which I liked better.

^Oh cool you tried them before? The PMX685 wasn't "great," it sounds bloated and lack shimmer, the KSC75 sounds better in every way, but note it was a literal earbud/headband. You could put foamies on it to make it even more bassy, so I would expect it to sound quite different from a hybrid canal 686G regardless of driver.
 
Great that they fixed the main flaw about it, the cable now I'm really tempted to get a pair. I would say these seem like THE pair of budget exercise headphones to get if you don't want your music to leak like crazy with the KSC75. Way better than Audio Technica's offerings.