I've recorded ALOT of techno over the past few years... w/ mics, direct patches, and matrix. Mics (as opposed to patching directly out of the dj mixer) does seem to add some "warmth" to the recording. IF you can, I would suggest standing in front of the PA with mics so more clarity is captured. In most cases, a pre-amp for the mics will improve signal to noise ratio and thus making a better recording.
The Mics... try to purchase something that is or close to full range (20hz ->20,000 Khz) cardiod condenser type that can handle a high sound pressure level like around 130 dB. Clubs are loud and bassy so you will have a distorted recording if the mics can't handle volume. Some mics will run off of the "Plug-in Power" (3-5v) on the MD, but most people use a battery box/pre-amp with or without bass roll-off to power them since they require more power to run.
Pre-Amp/battery box... anything is better than the MD's Plug-in Power. If you purchase a pre-amp or battery box, use the line-in on the MD, not the red mic-in. Some people run a box that has a bass roll-off option so the mics do not distort at bass heavy performances.
I am using these as examples because they seem to the most popular. There are better set-ups out there, but that maybe something you need to research for your self since I have no idea what you're willing to spend. For instance, the DPA 4061's are around $850/pair new.
Mics(L,R): "AT853-SP" (not full range, but close: 30hz-20,000 khz) $210/pair USD
Pre-amp/battery box: "SP-UPS-1" w/ level control $79 USD
Cable: 1/8" -> 1/8" gold mini-trs 1ft $15 USD
Grand total: $304 USD +S&H
The Church Audio equipment maybe something to consider since it's $199 for the Mics AND the pre-amp/batterybox. Not sure about the specs on the mics, so I can't list that info for you, but here's some photos:
In addition to a fair price, I have heard good things about the Church Audio Mics and pre-amp/batterybox:
I just finished rolling over my first show taped with the Church Audio rig and i LOVE these.
Thanks again Chris.
Check my thread on these in rig pics: http://taperssection.com/index.php?topic=71254.0
Chris was good to deal with overall and I would buy from again....his mics are solid and the st-9100 is very nice great toys
-Kevin