[T-N-T]

> One of the differences is that it doesn't even have an option to disable updates

Even if you could disable updates it doesn't matter because Skype is a centralized client-server architecture under Microsoft and I've personally witnessed friends who wondered why they couldn't use skype anymore on their computer because they had an old version installed of the desktop client and it couldn't connect to the servers anymore. Past a certain amount of time, Microsoft invalidates old versions and render them unable to connect. Whether it's by changing the protocol or just banning their ability to pair, I don't know, it's an implementation detail, the intent remains the same : update, update, update.

From that point of view of how it works in the real world, the RT version is an improvement over the desktop client because it's able to always remain updated without having to ask for user consent. There are too many users who don't say yes to updates and then ask why the software is broken and won't work later and I bet it has been a pain for people who work in the support side of Skype. The average user does not understand why the software stops working.