They want your e-mail address in order to download their free version. You can't go any further in the download unless you give one. They also have a paid version. Wonder what they left out of the free copy but included in the paid version?
I have looked at these comparisons in the past, they don't help very much. LibreOffice is a classic, they say its compatible with MS Office but it isn't, many times I have had Word docs turned into complete gibberish when opened in Libre/Open Office. I have also sent documents to MS Office users created in Libre/Open Office only for the recipient to complain that they cannot open the document or again its just gibberish when opened. SoftMaker has been the best for me, probably because its a MS Office clone.
Just as an aside to this discussion on Open Source Office Suites. I went though a few open source office providers last year looking for something comparable to MS Access. (I often use access databases for many tasks). The best open source database (none as good as Access) I found after comparing quite a few open offices, was BASE which comes as part of LibraOffice. It's a bit kudgy, but IS capable so you can even do master-detail (i.e. show details of a part in a separate form (form within a form) connected by a key). Very impressed by this - its also moving to a better SQL database called FireBird. Did get knocked over a few times though with one or two bugs and disappearing tables. Access is much better overall but all the security layering, signing etc... to make up for the innate lack of security in Windows is very discouraging - especially when you run the same database across multiple computers on a network share - which is where BASE and Linux excel.
I tried WPS Office a couple of years ago, I found it to be inferior to FreeOffice at that time. The 2016 version may be better, these office suites do leapfrog one-another, I will have to take another look.
Haven't heard of this one; I've stuck with LibreOffice on Linux so far but I'll give this a shot to see if it's a useful alternative.