What do you like best?
FileVault data encryption is built-in into latest version of MacOS and for this reason it's totally seamless. FileVault also uses the most modern data encryptions protocols what making it very secure.
What do you dislike?
In opposite to other data encryption software such as Microsoft BitLocker, FileVault seems to affect computers performance badly, even the latest generation of MacBook Pro with extremely fast SSD drives. Moreover, FileVault have a few "known issues" that several users reported and that we experience in our company too, where some computers refuse to boot because of some kind of corruption with FileVault, so we had to turn off encryption (de-encrypt all datas) to get computer booting back again and then turn it on again, then it work for a few months. We experienced this issue on MacOS Sierra (10.11) but not so far with MacOS High-Sierra (10.12), however since High Sierra is on the market for only 2 months and that FileVault remain unchanged in this version, we anticipate some issues later. Another known issue with FileVault is in business environment where computers are hooked to Active Directory for account password management, there's often some poor syncing between AD password and FileVault password causing headache to users.
Recommendations to others considering the product
If you need extremely high performance from your computer, such as movie or graphic processing, I would not recommend turning on FileVault because it surely decrease SSD speed by 15%. If you are having a older Mac computer with rotating hard drive, forget FileVault definitely.
What business problems are you solving with the product? What benefits have you realized?
FileVault improve a lot our data security especially on laptop computers that are always on the move and than are at higher risk to be stolen. Even with a strong profile password, anyone can stole datas by booting the laptop in "Target Mode" or by removing physically the hard drive/SSD. However with FileVault enabled, it's making data theft impossible.