Shure's first departure from its norm with the SE102s is a pretty obvious one; the design is entirely unlike anything preceding it. The business part of the earphone is a fair bit shorter, a bit fatter and the cable now runs from the middle, not the end of the earphone. As a result, the SE102s actually fit a bit more snugly in the ear, as they more closely mimic its shape. As Shure's design has you run the cable over your ear and then down the back, setting the wire in the middle means it protrudes less.
More annoyingly this change of design also extends to the 'sound channel' than actually protrudes into the ear canal. This is now far wider, meaning that no older Shure model's tips can be fitted to the SE102s. If you're replacing a set of SE210s, for example, you'll be throwing away your old tips.
That's an especially relevant point because Shure only supplies silicone tips in the box, which while pretty comfortable, can never quite rival the fit of a nice pair of foam alternatives. Third parties, such as Comply, will in all likelihood have their own tips on offer in the near future, but as a fan I'm disappointed they're not available off-the-bat, so to speak.
Having said that, even with silicone tips, the SE102s really are extremely comfortable to wear. The new design seems to enable the SE102s to nestle into the ear in a way even Shure's previous (very comfortable) range couldn't manage. Or so I think, asking around there are others whose opinions don't mirror mine. As ever, if you can try a pair before you buy to see if they suit, all the better.
Shure has stuck to its traditional modular design with the SE102s. As ever the longer part of the cable is thicker than the average cable, adding to the general feel of sturdy build quality. Incidentally, the plastic over the 3.5mm jack is cut out to fit a first gen iPhone, in case that's a consideration.
Overall, the SE102s fully live up to Shure's established reputation for building quality products. The only real downside of the new design is the move from a two-tone colouring to a single black plastic casing, but aesthetics are such a minor consideration when talking about earphones that it's hardly a huge problem.