The odd little issue has popped up with some of the monthly releases, but most have not caused me problems directly - they tend to be special use cases. I've been using Platinum since it was released and have had no show-stoppers. Very often, if a problem is found, a patch is released within a few days. I have taken to installing the updates a week or two after they are released, when most issues have been identified and any more serious issues have been patched.
To be releasing some quite major updates monthly, I expect a few bugs along the way. However, ultimately we are in control of the update schedule for ourselves - I wouldn't update in the middle of an important project. That said, you can roll back to a previous release with the CCC if you have to.
Generally, I'm pretty happy with how things are going.