I love it. I love the free version of the app, which allows you to view your spreadsheets and show them off. I also love the subscription version, which I tried out with the 30-day free trial. The subscription allows you to do most of the things you would normally want to do in Excel. Unfortunately, without keyboard shortcuts, everything takes a lot longer to do.
As an avid Excel user, it would be great to be able to make small edits to a spreadsheet on my couch with my iPad. But I would not start a workbook from scratch using the app, unless it was a very simple project. If Microsoft offered a one-time download fee of $40 (or maybe even more), I would gladly pay it. But I won’t use it enough to make the $100 annual subscription worthwhile.