In production, we only use one type of connectivity (database), but in development, we used some of the other types (file). When new major updates to the platform come out we need to update the connectivity software on our end (update our installed BirstConnect and jnlp files). Those only happen once or twice a year, but if we miss that or fail to test it properly there can me some minor issues. Not major, but enough that I would not feel comfortable giving connectivity a full 10.
We do keep an eye on the connection on a daily basis due to some issues we had with the cloud early on during implementation, but those problems all seem to be resolved. There is still an occasional issue where variables in a space passed to the connection query are lost (or even the full schema), but they are few and far between.