New Catalina download is making my Mac run slow. Anyone else experiencing this?

Not for me.

Few things to check: When it prompted you to install, did you select the right disk/partition? Check your disk space.

Check any applications running in the background/startup that maybe getting 'stuck'; try updating them or if not disabling them to see if there is any improvement. Use the tools (e.g. Activity Monitor) to check of any memory/disk anomalies.

Got to understand, Catalina is a different beast (mainly the dynamic shift to 64bit native) compared to Mojave and previous versions.

I am experiencing some issues on my MBA (early 2015) but not performance.

My iMac was running slow but I tried a couple of things , first I went in to recovery mode and did first aid on both system disks. second thing I Did was to prevent spotlight from searching my large (8tb) external drive.

Seems to have sped things up some . My next step is to add more memory and a ssd drive .

My Mac mini is blazing fast with a SSD drive and 32 gig of ram .