Been using them for years.

It’s completely free, open source and has:

• Unsupervised (for headless servers) or supervised (helping out relatives) access
• Easily file transfers
• Cross-copy paste
• Identification server (what gives out connection IDs) can be self-hosted or you can use theirs for free
• Can control PCs from mobile app (though not vice versa apparently they support this now!)
• Experimental web browser client.

EDIT: I forgot, but it’s also much better at compressing video effectively than realVNC, which is what I used to use. Performance and latency remains fairly good even at low bitrate.

For a little while, I even used to play point and click games remotely with my brother over it. Probably too much latency for an action game though.