Well is is funny. My brother owns a CrossFit gym and I have been shooting a video for him. We haven't gotten to the interview parts yet (soon though as I need that to help carry the story). I have been using mostly the onboard 7D mic for general ambiance. Not sure if I'll use any of that sound at all. Maybe, but only as B-roll at this point. But when it comes time to do the sit down interview I'll be using a boom mic over the top (Schoeps CMC6/41 or a Sennhieser 416) and a Sanken COS-11 lav mic connected to a Lectrosonics SMQV transmitter. And recorded at my Sound Devices 552 mixer. This is all part of my pro audio package. I'll also use the COS-11 and SMQV for when he is training other people or talking to clients. Maybe even if he is working out himself. Its all small, light wieght and sweat-proof.
As for the Giant Squid mics, generally most lav mics are the omnidirectional type, but I have used the cardiod ones too. Both can work, but I would tend towards the omni version. Take a listen to their sample recordings. The omni sounds a lot better and less "tinny" sounding than the cardiod version. But what's most interesting is that on the omni page there is also a audio sample of another mic, one called Iriver and that one sounds the best. Less background hiss or buzz. If that one is available in the omni then of those mics, I would choose that one.
WARNING!!! Honest Sound Snob Oppinion Ahead! WARNING!!!
...Don't read if you are easily offended...
But here's my honest, bottom line review from just what I've seen and heard of these mics on line. Personally, I wouldn't use any of these. For me and what I need to do with mics they are too big, awkward looking and that built in clip is a no go for me. Not every situation requires that the mic is seen or is clipped to the outside of a shirt, tie or coat. Stealth is my game. I do a lot of reality TV shows and I need to hide the mic and transmitter packs and even if I'm doing news or sports where the standard is to fully expose the mic head I still try to disguise it or not be so "Hey, I stuck a mic on someone, can everyone see this?" I like a cleaner look, but with no clothes rustle or scrapping sounds on the mic. And these GS mics are just too big for me. They also don't have a huge dynamic range. They sound a bit hallow with little low end and not very full. The omni did sound a lot better than the cardiod version, but not to the standard that I need from the mics I tend to use. Now for the money, they seem OK and I will give you that. They will work with your recorder in the pocket idea. But there are other mics out there that will also work for you and might be a better fit and more versatile. The Shure SM-93 has been spoken about quite a bit on this board and some here use these all the time. And Shure is a well established audio company. Also, you could order it today and get it by the early part of next week or sooner if you paid for expidited shipping. It seems there is a wait for these GS mics because the guy is making each one by hand. Nice, but that doesn't work for me. The Shure mic is a bit more money (probably less than $100), but the quality and speed of delivery are both more important to me.
I know I'm compairing my Broadcast TV gear to this mic, but that's what I own and know. It's what I do for a living.