Just a guess, but it might boil down to your preference between KT88's vs EL34's. From the few reviews I've read, the AT would appear to be a bit more romantic..... the Luxman presenting a more "modern" tube sound. In other words, just what you might expect from an EL34 amp vs. a KT88 based amp. In a perfect world, it would be nice to try both in your system and decide.