I am retired and use it mostly for texts, emails, and letters. Anytime I am typing or dictating whether on my phone or computer, Grammarly integrates seamlessly into the process to make suggestions. The suggestions are helpful and easy to dismiss should you decide to do so. I am not aware it has slowed anything down. I am using the free version and I feel it is an asset to my writing by helping me avoid punctuation, grammar, or spelling errors. I haven't found any downsides. See the example below which shows what you will see if Grammarly has a suggestion. I purposely left out the word "an".