I don't know about the Mercury but the Ios is the best dang amp I've ever heard. It works beautifully with my Trentes.
Are you also thrilled with Mercury Preamp?
I have had the DeHavilland Mercury triode tube preamp for about 3 months and I am amazed with it's very realistic life like performance. The instruments have beautiful bloom, timbre and solid imaging? When I listen to opera and jazz I am at the performance! Our others equally impressed. Please see my review and system elseware in this forum.