This may get a little long and probably confusing so here goes...
My test was done using constants. Everything was done using the same Artist/Album scheme, same sorting, same action windows (none), and things like that. So in my last test, there was a difference in how fast the same items were appearing.
Now in 27, things are definately faster but to me (now), the above scenario still exists. Now with viewing the root of Media Library, there's a huge speed increase.
Now I don't know what you mean by this: >>Adding anything with a tilde (~) to a view scheme rule will cause it to get evaulated in serial instead of parallel so it'll be much slower
Here's an example that could become a problem for a new user (not something I was referring to in the above test):
When adding a new view scheme, someone could add "playlist" to the rules. This is fine but the default playlist for me is (Auto Smartlists (music)). If someone would click on that, it would put that into the view scheme (by default), and here's what happens:
All the smartlists are shown in the pane, including the random ones. This is were ~ comes in: ~sort=random
When viewing this smartlist in a pane and clicking on random, the next pane (artist or whatever) fills up with random entries. This is fine and is the way things should be expected. What happens next is if you click on an Artist there, no results are displayed. The reason for this is I think MC is re-evaluating the ~sort (is this what you were referring to?)
So now is this something you would want in MC? Having fields not showing anything in the list? I have no problem with this but a new user wouldn't know what to do or know what happened.
This is why I thought MC re-reads the data in the schemes (panes). This was based on my example a few posts up. I thought the panes were slower than in the root of the library because there's nothing to re-read in the root.
27 is definately faster. You guys obviously done a lot of work. I really shouldn't be the one complaining about it. I'm using an old computer, have only 192 megs of ram..definately not the standard these days, and currently running at 185,244. I'm just trying to find out where this library comes in a slump. If it works fine on this pc, it should do the same on others.
Thanks again for all the speed improvements! The pane lists are now coming in at <2secs which is great!