Lehle Sunday Driver

Lehle Sunday Driver:

What are your thoughts on the SD? its like a smile boost that enhances the tonal properties of your natural, vintage guitar, or to smile out your guitar, bass or whatwver you want. its basically supposed to be the last thing on your chain or sit on top of your amp like a rangemaster is supposed to. its like a signal booster with a crystalline tonal property! What do you think about using it w/ a tube preamp, what characteristics will the 12ax7 or whatever behave like with the extended frequency reproduction?

and if there's a thread to what im asking about, drop that link!