ML 335 vrs ML 336

Need your best thoughts on possibly upgrading to a Levinson 336. presently have a 335. Wadia 860x up front playing through KEF Ref 3/2's . After upgrading from my old 331 there was a very noticeable improvement. Bass, especialy,seemed drop half an octave. Would I get a "worthwhile" or justafiable pop with a 336, or am I pretty much "Amped out" for this system ?(TaraLabs The One throughout and ded.20a lines)Thank you in advance for your advice. Jimbo