I started Crossfit this past Monday and go back tonight. I'm going to Crossfit 317 and I like it. M/W/Th this week and M/W/F next week are part of the 'kick-off' class to make sure you have proper form and to familiarize you with some of the Crossfit lingo and what not. For a bio-hacker like me who is quite familiar with various methods of training I mostly zone out when the instructor is talking and so far I've had great form (was even told I'm very flexible because I can actually do a full squat heh, thats because I work on one of my computers frequently on the ground and spend a lot of time in a squat haha), aside from zoning out during the talking bits it does make me feel secure knowing they are paying close attention to form and correcting bad form.
Aside from being sore as hell just from air squats, situps and push-ups I rather enjoy it and think it's something I'll be sticking with long-term (as long as finances allow anyway, at $150 a month it's a wee bit pricey).