Well, in my case I had already replaced both actuators. He replaced only the passenger so that may be his issue.

 

True, my point was that if one side was blowing cold and the other side wasn't, it has to be related to the actuators. If both sides were not bowing cold then yes, suspect low Freon and/or a leak. Low Freon to a point will cycle the compressor off and on and may not get as cold due to it not running all the time. Past a certain point the compressor will not engage at all. But it would still blow cooler air out both sides of the dash not just one or the other. If it just blowing the cold air out the passenger side and not the driver side, then its prob time to change that driver side actuator.
Using those quick kits the parts houses sell to top off Freon levels may be fine for someone in a pinch. but not greatest to be what I consider a correct fix. Over charging the Freon and ac system is just as bad as being low, it will also cause the compressor to malfunction and not cool correctly. Most shops have a recovery/charging machine, that isn't very expensive and are precise to the ounce, and will also pull a vacuum and make sure it holds to check for leaks.