Depends on the fish weight and the technique of the person with the rod.
There are two reasons why you lose fish at the boat - bad hook location/penetration and no pressure on the fish. Netting will save you from the first, but adds to the latter issue. Swinging saves you from the pressure issue, but magnifies the problem of a poorly hooked fish.
It's hard to do the first few times. You simply lift and swing in one motion. Don't lift the fish up and then swing because the rod torques funny and you can lose good pressure, plus the extra weight of the fish out of the water can make the hook location/penetration even worse of a problem.
If you're fishing for money (and rules allow), that net should be on the deck and your partner should have the net in the water waiting for you to get the fish to the boat. When money isn't on the line (or it's a cull fish anyway), do what you wish. If you're alone and believe the hook is in good, swing. 3 pounds seems to be the general "rule" that pros use for swinging... under 3, swing -- over 3, net.