I spoke to one of the guys at F-1 before buying my system, the guy said the Saver looks a bit crappier & doesn't breathe quite as well as the "formula 1" pipe. i.e. he said its designed primarily for offroad thumpers and the like.
He said i may be saving $100 by getting a saver, but i might not be happy with it in the long term.
The other ones up from the Formula-1 are really just lots of shiny stuff, I'd think about them if i had a newer bike & "bling" had some weight, otherwise i'd not worry whatsoever & just go the formula1 pipe

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oh and r.e. ADR versus non ADR compliant? i'd go ADR compliant with the baffle welded in, the things loud enough as it is. They said its 94db, but its a LOUD 94db!