Yes, Inderbinens are seriously good saxophones, it isn't just hyping of an over expensive "boutique" brand, there is something very special about them.
What I found is that the dynamic range is not just enormous, but as you play from one extreme to another you feel that you can keep the tone and intonation totally under control with complete ease. Intonation in general seems very easy to "hear", on some horns I play octaves and have to think very carefully about whether I'm hearing them in tune, with the Inderbinens I tried, it seems you can hear much better when the note is in or out, I presume due to the balance or tuning of the overtones.
I would have bought one on the spot, except that wasn't an option, the lead time was over a year.