Works fine, could be better
Open source is a good thing, and a bad thing. You are not at the mercy of one company and their product being bought by a competitor. There is a community working on improving it. And - you can choose a vendor that you like to help you make the most of it, if you don't have the expertise in house. And if that doesn't work out, you can get a new vendor. That's the good.
The bad is - something breaks in an update, you don't have anyone to blame. You can have a patch built by your vendor, can share the cost with others in the same boat or wait for someone else to do it, depending on how important it is to you.
We have a great vendor helping us with CiviCrm. The reporting is extremely okay, and most reports are pretty easy to run and understand. If you have a straightforward membership model, and run fairly simple events, or use it for donations, it works just fine.
But I do feel that it is not as nimble as it could be for a hybrid org, like we are, and some things just don't work well for us. I think it would perform better if you just have individual members.
