Well, I put 64GB in it and it's noticeably faster. The little delays when you do something are gone.
Pre upgrade, with one app (a small one) running it was using more than 16GB of ram according to task manager. It would have little 'stutters' when I did something, no graphic anomalies or anything, just slow ish to respond.
Now with the memory upgrade, it's still using the same amount of ram, but there's a ton of headroom now, it's fast and responsive. Snappy!
I believe that win11 NEEDS at least 32GB of ram just to be not paging to 'disk'. And I think I've proven it.
I know it's been reported that win11 is faster than win10, but it clearly needs a lot of RAM to do so. Not that this is a huge deal with modern hardware, but companies like Dell should take notice of this and have their minimum configurations such that the system doesn't encounter slow response times.
Hope this helps someone.