i bought the melos pre because i loved an sha-gold i'd heard a few years ago - amazing sound at the price, imho. for *me*, i'd buy the melos w/o even bothering w/the audible illusions. (of course, i *am* spoiled by having remote-control for wolume & balance - i now woodn't even consider a preamp w/o at least a remote wolume control!) several folks i talked with - dealers included, one who could sell me the audible illusions, said "get the melos", when i told them of a used one i was considering...
but, if i was in your position, drubin has the best adwice - buy 'em both, & decide for yourself. both products have a following, & yule have no problem selling the one ya tink isn't as good. i actually did this, buying my melos a week after buying a cary slp98. while i liked the cary a lot - better than the rogue 99, which has gotten strong positive reviews - i sold it after hearing the melos. the melos was in another league altogether, imho...
good luck, doug s.