Just keep in mind if you are mixing these down to two channels in the field and not tracking them to separate files on a 4 channel recorder, your going to get a delay between sources. Depending on how far your mics are from the stage, it can sound pretty bad. I ran 6 mics stage lip and the sbd feed this last weekend and even being at the lip, I wouldn't be happy with the recording without lining up the waves in post. Just an FYI
"Stage Lip" doesnt mean much as every stage is different...its still about distance from the soundmakers....
For the money - this is cheap and dirty way to get into multichannel recording.
Especially for small club/bar recording, you can make use of what are often unrecordable/incomplete soundboard mixes, and augment them with your mics...
Not trying to downplay the delay factor, but its not always a huge issue...