Originally Posted by DuckieTigger
2.3.1 works good. The only downside is, sometimes it takes a loooong time before books or collections are moved from the upper to lower pane - especially when all 5 items are selected. Is that a problem with the Kindle beeing too busy? Or maybe it is just a lot more involved under the hood to make CM work?
Yes, the copy/move operations are pretty slow - a move operation consists of the deletion from one collection, and the adding to another. Each of these database modifications is encapsuled in its own transaction, and takes roughly 500 milliseconds. Internally, this is anything but trivial... Plus of course, there is a lot of state handling happening in CM itself. So yes, it is normal for a "move" operation of 5 items to take about 5 seconds in total.
I have just tried to speed this up somewhat by encapsulating everything in a single transaction, but it only yields a marginal gain (~10 - 20%), and to properly implement it, half of CM would have to be rewritten...
So in short: yes, those database operations simply are expensive.