The Alpinestars SMX-4 Plus boot replaced my previous boots, which were also Alpinestars.
These boots are extremely comfortable (I could wear them all day....wait.......I have.
). They are vented to allow air to flow through the boot to keep one feet cooler than a non-vented boot. They fit pretty good too. They have plastic external ankle support.
Pros:
Comfortable (did I mention that earlier?)
Ankle support
Vented
Replaceable toe sliders
Cons:
Sometimes difficult to zipper if you don't have the lace tight enough.