McIntosh MR7083 vs. Magnum Dynalab MD100 tuner

I cannot decide between the McIntosh MR7083 and the Magnum Dynalab MD100 tuners. My system is McIntosh (MCD205 and MA6900) so the MR7083 makes sense but the MD-100 is current technology, looks great and sounds excellent. My local McIntosh retailer suggests I buy their pre-owned MR7083 for $900.

Someone told me that the "MR7083 has no real selectivity and he suggests I change all the IF filters so that it does, along with better fidelity". He also claims "the tuner tends to sound a little thin and distorted". Of course, this means more money is needed for MR7083 mods but I question if these mods are really needed. I am seriously considering the Magnum Dynalab MD-100 but I need some advise. What do you suggest? Thanks....