I never noticed the Algo section before and this seems like the most relevant section for Excel. I use VBA to develop. Excel is ubiquitous and my stuff is mostly based on skill in grid manipulation.
Anyway, I just installed a new computer and decided to try Office 365 because it was a 30 day free trial.
I have a routine called the build, where a large number of indicator levels are calculated for many stocks.
This took 6 minutes to run for about 20 stocks with Office Excel 365 - not a scientific result, I ran it twice (once with auto update off) and then uninstalled the product in disgust.
On Office Excel 2019 it runs in about 2 minutes.
That was unexpected because I had looked pretty carefully to find commentary on 365 versus 2019 performance and found nothing to suggest that that was even a thing.
I've been posting stuff on Stocks/Etf but maybe I'll move over here.