I have no idea what some of these negative reviewers are talking about...
I'll start with saying I was NEVER a runner and never thought I could be... I've been doing orange theory for almost two years now and i LOVE it. I stopped going for the span of about 6 months and went to a regular gym and the results from that were mediocre at best.
Orange Theory trainers push you beyond where you can go on your own and you never do the same workout twice! I never leave feeling like I didn't work hard and push myself, and I REALLY appreciate getting a challenging workout in one hour. I appreciate even more when I go in after a looong day at the office and I can just zone out and get to work because the trainers guide you the entire time.
Every class is unique and your body never adapts which is why these classes are so effective. The muscle definition and strength I have gained from going to OTF is 1000x better than what I've gotten at a regular gym and I've never been in better shape!
It is on the pricier side- but when I compare the cost to having a personal trainer at the gym vs. having personal training with 20 other people. I'll choose OTF every time. I look at fitness as an investment in both my short & long-term health and that is something I am willing to pay for, even if it means I need to tweak my budget a bit.
TL;DR - Give it 3-6 months. If you choose to challenge yourself- your body and endurance WILL transform and you will see/feel the results.