If this thing beeped rather than having a second unit it would be better in two ways: first it wouldn't force you to look at something; second it wouldn't need two pieces and bluetooth, and I guess the price could be sliced in half.
It has an open API which could be really useful on mobile apps, especially as smart watches and glass (potentially) begin to become more popular. So removing Bluetooth doesn't seem like a huge win. And the beep idea was probably considered (?), but it looks like one of their goals was to remove dependence on hearing.
Make two versions: one without bluetooth ($50-100) and one with (I guess the late bird price is $200). I wouldn't buy the bluetooth one, because I don't plan on using wearables (especially not cycling).
