I haven't used GNOME 3, but when I switched from 10.04 to 12.04 with Unity as the main interface I didn't have to learn very much in the way of a new desktop experience.
The point being that for Ubuntu at least the upgrade path didn't seem very painful. That's only one data point but I think the free software community is doing a better job than it might first seem.
Posted Aug 13, 2012 17:01 UTC (Mon) by slashdot (guest, #22014)
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That's because the Unity developers actually have to deliver a consumer product they care about every six months, with Shuttleworth putting his own money on the line and keeping them in check, so utterly crazy things are avoided or fixed once noticed.
On the other hand, GNOME 3 apparently has no such constraints, and the GNOME developers are clearly fond of taking full advantage of the situation.