In my experience, getting great guitar tone recorded starts with tweaking the amp until it sounds it's absolute BEST!!! I've done this significantly with my 5150 when I was testing out mic positions. Yes position is sensitive, but the amp must sound stellar before we even throw a mic in front of it.
For me, it's simply a matter of putting an SM57 between the middle and edge of the dust cap, then varying that position to what sounds good coming through the monitors, then putting the mic between an inch or less in front of the cab. This is assuming I'm going for a tight metal sound. So to me, mic position really isn't that difficult at all if you FIRST have a healthy amp that is tweaked to it's best, a good cab with good speakers, and good pickups. Oh, and a great player.