I read that with this mic, the cable between that lav and the transmitter is the antenna and covering it would cause interference. I usually have my interviewees slip in mic through their shirt to hide the wire, does that mean if I get this mic I'd have to let the wire dangle in front of them?

Also, any experience with this mic in busy urban environment (i.e. San Francisco)?

Thanks

You can hide the mic cable without problem. Keep in mind that metal or electrical fields between you and the transmitter can cause problems that are not related to whether or not the mic cable is exposed.