i had the rogue in my home for ~2 months, & no, it wasn't hooked-up incorrectly. re: its inwerting polarity, this is a wery minor diference that many people cannot even hear; many recordings inwert polarity back-n-forth on several tracks on the same disc, so ya really don't know what polarity yure listening to anyways. the only time yule run into a problem is if polarity is reversed from the left channel to the right channel. my melos m-d has a polarity-reversal switch on the front-panel, & i'd be hard-pressed to tell the difference between one & the other.
in my system, the rogue was quite coloured (this was enjoyable, ackshully, yust not accurate!), & there was no bass response whatsoever. i'm not referring to yust electronic/synth-bass, but, acoustic upright bass was m.i.a. i attribute this to an impedence mismatch; rogue sez the 99's output impedence is 100 ohms, but my real-world tests, crossing the outputs w/resistors, indicates 2-2.4k-ohms is more likely. this, combined w/18' i/c's from my pre to my 25k-ohm input x-over, is what i believe was causing my loss of bass response.
prior to buying the melos, i also auditioned the cary slp98 (rated output impedence of 800 ohms), and this was slightly better than the rogue in all areas, except accuracy & low-end response, where it was significantly better than the rogue, in my system. (also, testing impedence w/resistors in the same manner as w/the rogue, indicated the resistance is as claimed by the mfr.) still, the melos m-d is in another league altogether, imho... ( i was kinda hoping it woodn't be, ackshully - i *love* the looks of that cary!)
re: your friends' (dealers'?) melos sha-gold, i'd say it definitely is due for a toob-replacement, or perhaps somsthing else altogether different is wrong w/it? i've heard this unit, & it's anything but slow & muddy, imho - if it weren't for the soundstage depth & bloom, yude tink it was solid-state! ;~) i'd be innerested in your comments listening to it w/some gnu toobs...
regards, doug s.