How many times have you encountered the “Numbers Stored as text” error in your data sets? It interferes with your LOOKUP and MATCH functions, and arithmetic calculations. Excel has a Convert to Number functionality to help with this situation, but it could be a lot better. You have to deal with your columns one at a time, sometimes one cell at a time. Also, I noticed that if the dataset is huge, excel takes a lot of time to push through; occasionally, it is so slow that you can see the cells getting updated one by one.