Artboards disappear when using hand tool plus other gripes with v28.

Did the update to see if the following has been fixed:

When I scroll around any file using the hand tool, artboards disappear, as do guides when you're moving around. Then when you 'stop', it takes a few seconds to catch up and draw anything in. Yes, I've tried clicking and un-clicking "Real-time drawing and editing" in preferences. Yes, I've tried switching between CPU and GPU modes (all that does is send my fan into overdrive and slow everything down). This is so frustrating when you've got a big file with lots of artboards but no content or not a lot of content yet as it's impossible to know where you "are". This is a new behaviour to v28.x

Also, the general draw-speed of things is poor now. If I cut and paste an object, it appears in two places at once (if it works at all - sometimes it just doesn't). And I have to zoom in and out to fix it.

Much more frequent crashes also - especially with larger files.

I have again rolled back to 27.9.3, which fixes all these problems and is generally more stable.

@Adobe - Can we please get the version fixed before adding more AI bells and whistles that no-one has asked for. Most of which I can't use anyway because they're not available in the stable release of the app.

I'm on a fairly new (last year's model) Dell XPS laptop with 32Gb memory and a Core i7.