Unless you want to sit around for 30 seconds waiting for the spinning beachball to disappear every time you try to do anything in MC do not get tempted to install a Sequoia Beta.
The 1st Beta is just under 15Gb and takes around 90 mins to download, prepare and install and there isn't any AI built into it yet so who knows how big Sequoia will be when it's ready for Public Release.
Things I've discovered so far:-
The prepare stage now has it's own screen and the final step of the Install takes over 10 minutes.
When you start MC up the MC window pops up immediately and you can switch between the entries on the Tree.
Thumbnail based Views, Like Albums and Artists appear almost immediately, on previous OS Versions the beachball would appear.
Now for the bad news - if you click on a Menu Header or any button that is not in/on the Tree the spinning beachball will pop up and remain spinning for about 30 seconds.
Unless the item you have clicked on has a "menu" that has other "sub-menus", the beachball will reappear and spin for about 30seconds while the sub-menus gets loaded.
And that spinning beach ball causes the UI to freeze while it's on the screen. What's even worse it does it every time you go anywhere near anything that causes the beachball to pop up.
Thankfully there are 2 places where the "Dumb Intelligence" Apple appears to have built into Sequoia doesn't have any affect - Clicking the Spotlight Button and Clicking on the MC Ultra TI's Menu's do not induce the beachball to put in an appearance.
Some more DI Stupidity - If the user hovers the mouse over a Multi-Stage Button or any text that gets highlighted when the mouse is hovering over it the spinning beachball will put in it's 30 secs appearance when they move the mouse. Oh and it will also happen if you use the mouse to adjust the Volume or Position Sliders.
So far I've only been able to do a limited amount of checking, that spinning ball was getting on my nerves, but my present thinking is that Apple could give Snails/Slugs lessons in doing things extremely badly/slowly. It took me over 2 minutes to switch from using the Mac mini's built in speakers to my Samsung Q990D Soundbar and switch of everything in DSP Studio.
I'm hoping Apple solve the very obvious inefficiencies I've already found before the Public Release because if they don't it is going to take Bob ages to come up with versions of MC that overcome whatever stupidity Apple have built into Sequoia.