It's a great place to work, but in the interest of full disclosure I'll list the cons I can think of.
Sometimes the hours can run long, and sometimes weekend work is needed. It is completely dependent on the contract. Most of the time it's 9-5 weekdays, but it can change. The overtime and holiday pay helps make this bearable, but it's still never fun to work the odd 10+ hour day or Saturday.
Sometimes benefits are a bit quirky. For example, you can't have overtime on a week where you're taking PTO. If you work 40 hours over 4 days and take Friday off they will charge 8 hours of your PTO for being out of pocket on Friday, but they won't allow you to take 8 hours overtime for the extra work earlier in the week, so basically you lose a full day of PTO and don't get the extra overtime bonus for the 8 extra hours worked Mon-Thu, you will only get paid the normal 40 hours but still dinged on losing a day of PTO. If you work here you just learn to never work overtime on a pay-period where you're taking PTO.
You'll never be certain on the time or energy requirement to expect next week. Some weeks there is downtime for training or exploring new tools, because our clients don't have tasks for us immediately, and other times you'll be having to work overtime or weekends to get the job done. Improvix does try to give good work life balance, and usually they succeed in being very flexible, but the commitment of hours per week can change drastically, which doesn't work for everyone's schedule.