Sorry for the time machine thread bump but...
I found this thread while looking for some Horowitz recordings worth buying and wanted to offer another personal (sort of) link to him. I can't remember the year or how old I was. I think I was 9 or 10 at the time (1991 ish). The music store where I bought my Suzuki Method books for Piano lessons actually had his Steinway D in the store. I got to play it, and at the time the newest song I had learned was Linus and Lucy by Vince Guaraldi. I wish I had been older and could have appreciated the feel of his piano. I do remember that the keys had a fairly short stroke, and that to get any volume out of it took a great effort (at least for a young kid), but that you could play it while hardly touching it as well. I've played on Steinway pianos for years in college and various churches and have never played one that plays as I remember that one playing.