With the purchase of Permanent Pro, you gain access to Dropbox and OneDrive, and you can export files in XLSX (Excel), CSV (comma-separated values), and TSV (tab-separated values) formats. You can also save documents as PDF to share them as read-only versions.
Unless you need support for Dropbox or OneDrive, or need to create/export in other formats, you'll be fine with the free version of Permanent. There are a lot of features here, and getting them all for free is a very good deal.
On the other hand, Permanent 2 does not offer charts in either free or paid mode, so if your spreadsheet needs include charting, you'll have to look elsewhere.
The bottom line
In my time with Permanent 2, I found it to be easy to use and relatively feature rich. With Box, Google Drive, and Evernote cloud storage in the free version, it's easy to keep your work accessible from anywhere. If you need the capability to create native Excel files, you'll want to purchase $10 Pro upgrade, and if you need charts, you'll want to look elsewhere. But for a straightforward spreadsheet app for iPad, Permanent 2 will probably meet your needs--and since it's now free to use, there's no risk in trying it to see if that's the case.
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