Comment by adornKey

Most likely it depends on what you want to do. I used LibreOffice a lot (mainly Calc). A lot of areas were surprisingly buggy, but in some important areas it had more advanced features than Excel and performance was great.

One thing I learned was, that there is no compatibility. You can load some files from Excel, but to get something done, it's better to start a new file from scratch and import the data from csv. As soon something is more advanced (like configuring an axis of a diagram) it's all different.

Most important - CSV-Import in Calc is something that works just fine in LibreOffice, while the CSV-import in Excel has always been hardly bearable.