Jon wrote:[which, if either, is the "better" way of getting a decent starting guitar sound?[/a farily unrelated, and possibly stupid question]
The best way of getting a decent guitar sound is to place the mic where it sounds best.
Now that I've typed that I feel that it's a stupid answer to a normal question.
But seriously, have a friend or a remote controlled robot move the microphone infront of the best sounding speaker up and down, back and forth. If your friend is wearing headphones, you can dictate him from the control room what to do - just like a robot. Let him/her/it leave the microphone where it sounds best. Easy.
I've read in a book about recording to place the SM 57 in a 37 degree angle to the spot where the cone meets the centre of the speaker.
That's what I call a stupid advice.
Best, Max.