I'm in the market for a used amplifier to upgrade from my current audiolab 8200a....i've heard the Rega Elex R which I liked and I would buy that new and gets rave reviews but I've also seen that some of the older model Musical fidelity and M6i Si models are at good prices. Can any MF owners share their thoughts? I have a collection of speakers at the moment of : Proac Super tabs, Spendor A5's and a pair of Proac Response D15's........I know my amp needs an upgrade lol. Thanks in advance!