If I am looking for a ready-made CMS I will look at what exactly I need one to do as well as if it is something that covers my needs now and into the future. I try to find something that I don't need to switch from later because a particular need isn't met. I also make sure that the things I need one to do are done well and there aren't any major issues that can't be fixed, changed. modified or altered to fit my exact needs.
I also look for one that has things easily available including themes, plugins, add-on's that I need or might need into the near future. I don't want to spend time and money on setting it up then find out I need to change to another CMS later down the road.
I always research what I might use to make sure it fits my requirements before deciding on going with any particular CMS. Preparation is key when choosing a CMS.
