For us, OR worked with all our parts. Some other channel managers didn't. It also did not charge a lump sum to set up. The calendar is nice, the rules work well too. There are ways around non API channels, so they can be included. Tech support is great. I've come to know the people there as I've had lots of questions.
Channel Manager software is a must if you have multiple properties. The trick is to find the software that works with what you are using. In our case, OR worked with our dynamic pricing software and with our channels. A lot of other software programs didn't, or offered us things we didn't need. Do you homework by deciding what you need and then find the software that works for you. For us, it took a few tries, but we found our solution with OR.
It's a lot to learn, especially if you are new to this tech. There may be easier programs out there, but in the end you need to learn how Channel Managers work. At times, we just wanted to reduce our channels or give up entirely, but Ken at tech support was always quick with an answer.