LOL, do you know how many times I heard "well 20 tube watts is way more than 20 solid state watts", lol I don't know how they figure it out, but more power to them... I run a tube amp and own a couple of them, a carver and jolida, I think I prefer the jolida, but for ambiance and looks and feel and just coolness, the tube amps are awesome... The trick to them is run efficient speakers, towers normally and keep them in a well vented area, not near heat ducts or radiators and they will last a long time...
Another thing I hear all the time but find is true about tube equipment--- "If they are not breaking in they are breaking down" keep that in mind, lol...