We have worked with a number of artists using these tower array systems like the Bose L1 or the Fishman SA330x. There are a lot of benefits to these portable systems, and they have great sound quality that suit our mics well. The main thing to keep in mind, though, is that when condenser micing the claim that you can have the column behind you without concern for feedback is not true, especially if you're single-micing where the required gain is pretty large. Having a mic with the sensitivity and gain to give decent volume to an instrument 3 feet away, pointed at a reproducing speaker only an additional six feet away in the same direction, is never going to work. However, people have had success placing the column just about level with the mic, not too close, especially if they can angle the mic a bit away from the column. Generally you can then hear yourself well enough from the edge of the column's pattern, but the mic and the speaker are both in areas of lower sensitivity with respect to each other, so you can get the volume out to the room pretty high. You can also add a floor monitor out in front of you for added volume on stage.