Given my setup, does anyone have an opinion whether upgrading to the PM 14s1 would make a noticeable or just a minor improvement? Going from the PM8005 to the PM 14s1 costs 2 1/2 times as much - is it worth it?You pose a tough question. I have nothing but respect for the PM-8005 & PM-8005. In fact, I was so impressed hearing a PM-8004 driving a pair of 10K Sonus Faber Cremonas, it led me to the PM-15S2. Which is near identical to the PM-14S1. So I bought one.
Your Focals are pretty efficient and you probably wouldn't notice the extra power the PM-14S1 brings to the table. But you may notice its preamp section so I would definitely audition one if your able to. Also, as you know, seldom do we experience quantum leaps in performance when upgrading in this hobby. Its usually on the magnitude of only 5%. But its this elusive 5% boost in performance that keeps us in the game.