I tried out Grammarly along side ProWritingAid and found it better meets my needs. Of course, both have developed significantly since then. PWA feels more grounded and gave me better suggestions than the competition. I bought a lifetime subscription. I have it turned on, on most webpages and in Outlook, Word and PowerPoint. It supplements the MS editor well. When I have needed help, the support team have always been great.
Pros:
I like that it integrates with my favourite apps and is available whenever I am typing.
Cons:
It is brilliant for novelists and other fiction writers. I would love some of their functionality focused on business and non-fiction writing.