A potential benefit of AC being cloud based is that it should make upgrades seemless.
Agreed. First, it means that you don't have to do a thing; you just log in one day and the latest update is installed.
In addition, there was some discussion of this at the Tahoe meeting during the period where many users were unsure about whether to upgrade to the most current version because there were so many problems with it. Under the right circumstances, you might let the provider "vet" the new version and make the call as to when the upgrade should be undertaken. If your cloud version is maintained by a knowledgeable, trusted provider (again, I use Indy as an example), you might let them decide (not even necessarily AC) when it is appropriate to upgrade.
I think the issue of upgrades, based on the past, would be extremely difficult. And, I don't know how one and a group of people would know who would want one upgrade. I think to wake up on day to v6 with all of its problems would be an issue. Of course, there would be less since it would be on one server and hopefully tested over and over. I am used to having the choice, but this is because I have never used SaaS programs.
What we do, and what I suspect JBS may be referring to, is how we do upgrades for our clients; local or hosted. We notify clients when we have tested an upgrade or beta, and based on how their practice uses AC, their setup, their appetite for "new and shiny", we have a discussion/recommendation on whether it is a good time for them to upgrade, and then we schedule the upgrade for off-hours. It either goes fine [or not], and they either have the new version to run with, or we roll-back off-hours and they have the old version they were running when they left the office. It is their practice, their call; we work to serve that practice well and "Make it so."
We bill services, but ultimately we are in the solutions business; Technology is a tool towards that end. It is as seamless as we can make it once the Doc decides they want the upgrade. They may try it over a weekend, and decide they want to roll-back instead.
Among our clients I think we have almost ever Release and Beta between 5.0.26 and 6.1.2. We have our own internal perspective about their relative merits and blemishes, but our job is to keep the trains running.
