In my mic collection, all my inexpensive condensers tend to emphasize any high end harshness that exists in the guitar, player's style or room. They can work well though, if there isn't any upper mid edginess. Just for perspective, some higher end condensers like Schoeps (and especially ribbons like the Beyer M160) can be more forgiving in that aspect and still get all the detail w/clarity. My MXL 603, V67, B'er ECM8000, Rode NT2 are all good mic's but get jangly/edgy if the source has any roughness in the 2k-5kHz range.
As far as mic location, for steel str acoustic I think the neck/body joint is the general location that works well for most gtrs when you're close mic'ing (less than a couple of feet away)and it's considered somewhat of a standard starting point, as you'll hear in the thread. Gets a nice balance between lows and highs (and can make a mediocre instrument sound better than it really does). Adding a 2nd mic in XY at that spot gives added complexity to the sound without causing phase problems if you pan them together. Adding a 2nd close mic at the bridge and panning the mic's L/R give a wide sound and fills in the lower mids to my ear.
When you move the mic's a few feet away you get the whole sound of the gtr and how it interacts with the room, which can be a good thing or a bad thing. IME you've got to have a good sounding room (usually needs high ceiling, large floor space) and pretty good sounding instrument. If you've got a good room, moving the mic's a few feet back and using XY or ORTF config can get you a very open, you're-there-in-the-room sound. It can also can reduce the mic's pickup of any edginess that exists in the source, as that often dissipates with distance in a good room.
I’m assuming that it’s an acoustic steel string, not acoustic nylon. I record 30% steel str and 70% classical/flamenco gtr. Nylon strings can be pretty different for close mic’ing.
Tim