Some great stuff on this thread. Here's a couple of points. One is that the sound hole acts like the bass ports on a speaker cabinet; ie it lets out the sounds below a certain frequency (depending on it's size and the internal volume of the box) in phase with the sounds coming from the front. Hence the interest in Tony Rice's enlarged sound hole Martin - I believe they make a model incorporating this.
Another thing to consider is that the tonal differences caused by the way you hit the string only last for a few milliseconds, but the subjective impression lasts for the full length of the note; the full tonal effects of the guitar design and build etc. soon get excited (just like us). I remember hearing on the radio an experiment where a steel string, a classical and an electric guitar were recorded and played back without the starting transients, and it was vitually impossible to distinguish between them.
And another thing! to do with aging. I have heard (don't remember where, sorry) that arched top tailpiece instruments like jazz guitars and fiddles age much more slowly than flat top pin bridge type ones; the difference being something like 300 years to 60; so the secret of a Stradivari is - the person who can build a 300 year-old instrument has cracked it, as it were! This seems to contradict the opinion expressed above of the Scotsman who built fiddles that sounded like Strads, but that's the wonderful world of wooden instruments for you.
The more you learn, the less you know!
Cheers, Richard