...wasn't sure if you were talking to me, Luis. The Audio Technica I bought was just an inexpensive clip on condensor, the Pro 70, which is marketed for acoustic guitar (used by many gypsy jazz guitarists in Europe), and addresses the feedback problem with the standard pencil condensor mics on stage (at least as a primary source for input). For a higher end condensor mic, I bought the Sure KSM 137, recommended by a Sure engineer who plays archtop jazz guitar.
The two Audio Technica mics that I consdered were the large condensor AT 4050 (multi-pattern large diaphram), which I think is an outstanding mic but overkill for what I wanted to do. http://www.audio-technica.com/cms/wired_mics/194ac5d60380d624/index.html (I still may get one, for recording).
...and the Audio Technica pencil condesor mic, AT 4051b condensor. http://www.audio-technica.com/cms/wired_mics/7a24561e8865117b/index.html
I decided to go with the Shure, however, based on my discussion with the Sure enginner and the fact that he was using the mic for exactly the application I was intending.
All these mics by Sure and AT in the $300-600 range are really good in my opinion. I just took the leap and picked on based on comments.