Bryston's 20 year warranty always stood out as the strongest statement in the industry.
Back in the Dan D. days, I remember driving my Krell amp to their CT facility for repairs, as I lived not far. The reaction was undocumented policy, but basically their team at the time implied that their stuff would always be fixed at no charge. Surely, the new regime doesn't hold that attitude.
FWIW, although I've heard plenty and owned some Audio Research gear, IME their service / upgrade policies are closer to price gouging than to "tops in their class". There have been plenty of posts here and elsewhere from folks less than pleased with A. R. after they've bought from them. Again, only opinion, but I'd never recommend their gear for purchase unless it was used/depreciated already and I had a service technician that I trust if repairs ever were needed. Cheers,
Spencer