One of the drawbacks of this system is that the client effects and the actual actions are now separated. Before you click, the next tick would happen, your input would be collected from the OS, actioned, and the effects would be triggered. Now, you click, and it's immediately recorded into a record with its location and direction with a timestamp, the next time a tick happens the effects play. This means the input might feel a bit different due to that separation. It is possible to shoot in between renderings. So you are essentially shooting blind. This is where input might feel weird.

In CSGO if you ever catch yourself clicking that millisecond before you render, knowing that your crosshair will be on the right exact pixel in the next frame you get, and thus getting a headshot, that will now miss.