When I bought my REF 75, I compared it with a 110 and the difference was really quite large. I also had time against a REF 150 and again I preferred the 75, though it was'nt a better sound, merely one I preferred, the 150 certainly had better grip on the Wilson Duets, used in the demo. I believe in years to come it will be referred to as one of the great ARC designs, as say the D70 is now.
I upgraded to the 75SE about 2 years after purchase and the sound is better, I'm sure, but as it took about 3 weeks, my aural memory is'nt that great over time.
As to ARC gouging it's loyal customers with upgrades, I was told by the UK Sales Manager that I should'nt use my quad of 150 tubes bought from Upscale audio, as the matching would'nt be optimal. Silly me, thinking all those years that matching was what the bias adjustment is for.
Looking at the question of upgrades from ARC's point of view, there just is'nt a mass market for high end audio any more and there is never likely to be one again. As a business model, a stream of expensive upgrades for existing models makes perfect sense. Perhaps that's why they are one of the longest surviving high end manufacturers in the world.
