New 16" MacBook Pro - Running Slow

Hi,

I just picked up a new MacBook Pro 16" (Base Model - 9th Gen i7, 16GB RAM, AMD 5300M, 512GB SSD) for my fiancee yesterday from the Apple Store.

I work with MacBook Pro's at my work (repair them, troubleshoot, run software installations and updates), with models ranging from early 2013 Pros to early 2019. However, when we set these up for new users, they are preloaded with a bunch of apps.

Setting up my fiancee's new laptop, we used the migration assistant from Windows to Mac, and moved over her files. When I rearranged them to make them easier for her to find, I noticed that the Mac itself was sluggish. Specifically in opening up different windows, it seemed as though they were stuttering when opening, not the smooth transition I am used to at work. I ran the most recent MacOS updates before proceeding and I'm thinking it has something to do with that? Has anyone else experienced any sluggishness on the most recent version of Catalina? We're still stuck in Mojave at work (can't update until we get all of our security apps up to 64-bit).

Thanks for any input!