If done on a local network it works really well. Hosted a LAN party this way as we didn't have enough TVs / Monitors for each PS4 but had a couple laptops.
If done over the internet the delay can be for a second or more. If the connections on both ends are good enough then some games are very playable. Fighting games like Tekken or Mortal Kombat being good examples. Competitive games like COD are not playable at all because of the delay.