Thank You very much for your long and informative comment! The only 2 Apps from KDE I use are kdenlive and digikam. Both are not running smooth. That was one reason I thought about installing KDE and Check it out.

I didn't Upgrade the Hardware yet. I have a 256 GB SSD in it with 60GB free at the Moment. I should reformat my external SSD to ext4 I guess. I got the ThinkPad in Africa and here is it not easy to get a SSD. So I will do that when I get to Europe or USA...

I would do many things again, but there is a lot I would do different, if I go back!