Yikes...loaded question!
Generally speaking, great when it works. I've seen two major issues with it though.....the first is hardware/platform longevity, and the second is training related.
We all suffer through the fact that ALL of our computerized systems run on PCs which, within no more than 3 years, are so outdated that replacement parts are often hard to come by. As Software manufacturers create or modify their product and bring the broadcaster new features, what often happens is that the existing platform will not support this, and so the station is forced to make another investment in hardware and the change-overs are quite often not as painless as advertised.
Then there are the issues on the station end. Training is a huge issue. Often there's only one "super user" who really knows the automation system...making his or her life miserable at times.
I know there are "complete" systems out there but what mid and small market station can afford them?