I'll be honest, the price for a monthly membership is pretty steep. There's no locker room or showers which I know is a few points off for some. That said, it's a pretty great workout with some generally fun people putting you through your torture, I mean routine.
I went to a 9Round in Oregon for a year when I lived in Portland. Almost none of their trainers had any boxing or kickboxing background and it showed. Some people will never put forth the effort to learn form or technique or even see the importance or value in it. But I saw most people in my Oregon gym flailing at the bags and here I mostly see people hitting and kicking with at least an attempt to do it right. I put a lot of that down to the trainers. Michelle, the owner and Lacey both have a boxing background while Zach has a kickboxing background. And I've seen all three of them with first time newbies. They actually teach you form!
Admittedly, Zach is my favorite trainer. He knows I generally know what I'm doing in terms of basic form and finds ways to challenge me when the opportunity arises. I've spent the least time with Michelle but she's been pretty mindful of my new asthma (so has Zach, he hasn't all out killed me yet!) since I returned to the gym recently. Lacey is a generally rad lady who I've had almost as many workouts with as I have Zach and while she doesn't challenge me as much as he does she doesn't let me slack and makes sure I'm working. All three are great people to get your sweat on with (or to chat idly with before or after you die on the mat).
I wholeheartedly believe 9round is a workout where you reap what you sow. If you take the time to learn form, work on your technique and go as balls to the wall as you can then you will be dripping sweat on the mat by round 6. You can easily scale your difficulty up or down based on your abilities and current fitness levels. The trainers are great at adapting for limitations and injuries as well.
I know there are some new trainers but I either haven't met them or haven't had much exposure to them so I can't really remark on those couple folks. You'll get a solid sweat session in with any of the three I mentioned. As a bonus: hitting things is a great stress reliever!!! Though you might manage to skin your knuckles even with wraps on (and your elbows and your knees).