It's not fair, Manon. I've suffered through small hands all my life. When I was young, my mother couldn't find a piano teacher who would take me because of my small hands. When I took ballet, they didn't make shoes small enough. When I was in 3rd grade I weighed 38 pounds. I'll never forget because we did some sort of class project and everyone laughed at my weight.
Not only are my hands small, but the bones are thin and my thumb doesn't open very far. If I had larger bones, I believe my reach would be better.
And yet I love the piano and I always have. To me it's the perfect instrument. One of these days when I win the lottery I'm going to get a Steinbuhler and finally play all those pieces I've wanted to.
Right now I'm afraid to teach on one even if I could afford it, because how can I help my students perform on regular pianos if I teach on a smaller keyboard. You would have to have 2 pianos in your studio, I guess.

Ahhh...the joys of having tiny hands...haha. My fingers also don't open far enough. I'm kind of disproportionate since I'm small up there (hands included, of course), but big and wide in the middle and I have long legs. (Wish they were fingers instead...)

How many pianos do you have in your studio? (I have one grand, one upright, and a synth.) If you have two pianos, you can use one regular one and you can fit the Steinbuhler on the other. (Yes, you'll still keep your original piano--you only change the keyboard since it's removable. The technician does that kind of stuff. I believe that's what I read on the website.)