Like Kevin, I also had the experience of working with Marks F-14s. Mark had a smaller version that I flew here on the slopes as a glider. Weighting the tips, was the easiest way to go. Having flown with and without weights as well, I can tell you from my own personal experience that if you dont, then the pitch response gets really slow if you dont shift some weight aft. On a third model, we used some heavy paint application on the wings and that did the trick as well.

Best of luck,

Ray