Dave and Bill,
You fellows are too kind. As you know, I am a big admirer of both you guys, not only for your wonderful music itself but also for the fact that you are actually doing it...putting in the hours, busting your humps to create the very best music you can. It's the kind of inspiration that could ultimately get me to get over myself and join the party.
Bill, your thoughts on the need of composers to actually understand the nature of the instruments they are writing for is right on. Rimsky and one of his buddies (can't remember who) made a point of learning to toodle a bit on every instrument of the orchestra, just to get a feel for how they made music. Last I heard, he was considered a pretty fair orchestrator 😉 I like to say that good orchestrators give the instruments parts to play that match the temperament...the personality...of the instrument. This means a lot more than keeping the part in the useable range and keeping the limits of the ax's caprice technique in mind. It means that if you're going to write a horn part (for example), no matter how original and unlike any that have come before it, it still needs to be "hornistic." In Don Juan and Till Eulenspiegel, Strauss asked the horns to produce licks that had never been dreamed of in an orchestral setting, but the parts were perfectly hornistic (it didn't hurt that his dad was one of the top hornists in the world).
As Bill points out, the world of virtual orchestration is a place where the composer really needs to watch it, because MIDI is perfectly happy to grind out any stupid lick you may program for any instrument...even though the "wrongness" will be obvious to anyone. There is a chap who used to hang around this list...you know the guy; bit of a piece of work, fancied himself a provacateur...who put together an impressive collection of unknown classical works by unknown composers and put them online. When the VSL Historic Winds release with the natural horns came out, he found a couple of little-known horn concerti by a worthy named C. F. Abel and dutifully cranked them out. I was digging his effort...the strings were tight and nicely balaced with a clean, chamber orchestra sound, the horn solo was singing along with nice phrasing. Then...the closing allegro arrived. His tempo was so brisk that the ghost of Punto himself would have cried "Uncle!" This cat Abel must have been a cracker-jack virtuoso (or was working with one); his chart is chock-full of arpeggiated figures climbing to the highest register of the Eb horn; real show-off stuff. But at my man's computer-assisted tempo they popped out with a blatantly artificial perfection; every note absolutely centered, no discernable difference between the stopped and open tones, runs and arpeggios rattling out with machine gun precision. It was, to me, comical. Despite the fact that he was working with an actual historical piece of music, written by an actual performer of the era, and despite his obvious skill with sampled orchestra production, my man had rendered his work unhornistic.