the fremer review was in the january 2011 issue of stereophile. i've been looking for the online version because the paper copies got pulled from vendor shelves in the middle of january.
i can believe that the kleos would sound different from the delos. the kleos has an output voltage level of 0.5mv vs 0.6mv for the delos: this suggests to me that the kleos has fewer windings. there are undoubtedly tradeoffs in this stuff as jonathan carr has described, but i can believe that the channel separation for the kleos would be better. the intrinsic resistance of the kleos is also about 35% less than that of the delos but it's not clear to me how much difference 2.5 ohms will make in the sound given that typical phono stage load impedances are going to be well over 100 times that amount.
i'll try to take another look at the sibilance thread because i had previously glanced at a few comments and a hard time understanding what the problem was. the delos does have a thinner stylus, which suggests to me that it digs deeper into the groove and might track better than the kleos.