Sedond sold his 99 because he wasnt happy with the bass.I have BDR #4 under my 99 and invested in real good NOS tubes for the phonostage (Telefunkens) My bass is awesome,deep,tight and real sounding.The reviewer in the Oct. issue of Stereophile was quite impressed with the bass of the 66 he reviewed and gave the 66 a class B rating.Anyway,yes the 99 is a good leap ahead of the 66.Get a 99 and you will be blown away.Call Mario @ 914-421-0069.I promise he will give you the best deal around.Tell him Dave (tube rush) sent you.