In reply to RBK:
> Good review Rob, can you give any guidance on where these sit relative to the Instinct VS in terms of fit and stiffness?
I meant to include this in the review, as I had a feeling it was going to come up, but then the review was already quite long and once you start comparing it to other shoes, where do you stop?! That said, more than happy to answer it here, as it's probably a more natural place for it to be posted anyway.
The Boostic/Instinct differ in several ways and I'll cover each in turn:
Assymetry
This is potentially the most obvious point of difference, insofar as when you put them side by side the contrast between the two is hard not to notice, with the Instinct being pretty much straight compared to the radical levels of asymmetry in the Boostic.
Toe Profile
The Instinct features a centralised toe profile, whereas the Boostic's very much focusses on putting power through the big toe.
Support
The new Boostic is definitely a stiffer and more supportive shoe than the Instinct, partly because of its full length sole (the Instinct, in comparison, features a split sole which helps to provide more sensitivity). However, it's neither as stiff or as supportive as its predecessor...sadly...
Sizing
I went a half size up from what I wear in the Instinct to what I wear in the Boostic, which felt about right.
Hope that's of help!