Recreational or 'sport' boots are roomier and warmer, while performance/race boots are stiffer, narrower, and often feature carbon cuffs and soles that make them super lightweight. Almost all boots have a quick-lace system, a zippered lace cover, and a hook-and-loop or ratcheting ankle strap. Some race boots have instep ratchets.
SNS Pilot boots, which feature two bars, or 'axles' and a full-length depression in the sole that inerfaces with a ridge on SNS bindings, work with Profil and Pilot bindings. Single-axle SNS Profil boots work only with Profil bindings, and NNN/NIS boots only with NNN/NIS bindings.