anyone use the bat vk-75?

please describe your impressions of this product including its general "sonic signature" as you hear it. what other equipment did you mate to the vk-75? how many hours can one expect from the stock tubes? how much for retube?

a local dealer has offered a "lightly used" demo for ~$3k (list is $6k). what do you think? i intend to use the amp to drive avalon arcus speakers. other stuff includes meridian 508.24 and (probably) bat vk-3i/5i/30 pre-amp.

any advice is appreciated. thanks.