As a 48 LRC owner for 8 years, having searched for one for 3 years before buying, let me off another view. The hull shape is different from the planning hull design of most Hatteras boats. The best way to see it is to get positioned just behind where trim tabs would be mounted and sight down the bottom of the boat looking forward. On the planning hulls, you will see a almost straight up hill run to the bow along with a keel that is also essentially flat on its sides going forward. Next look at the same areas on an LRC. The bottom looks similar to a sail boat hull. From the bow the hull contour runs down hill to about mid ship and then starts to ascend as it continues to the stern. The keel is also deeper and much wider. The keel base also widens at the area where the hull bottom is deepest. The running gear uses larger propellers and much larger rudders. The gear ratio is also deeper. Overall, it looks like a sailboat hull, terminated 10 feet sooner at the stern, with a semi hard chine the aft third of the length. I would be interested to compare the LRC and the bottom of one of the sail boats Hatteras built back in the 80"s. I would categorize the motor yacht hulls as planning. They have a sharp entry, have hard chines the full length of the hull and a constant dead rise. The primary factor that makes them run in semi displacement mode is the power weight ratio. I once docked next to a brand new 1984 53 flybridge motor yacht, with 435 HP 871TI engines. That boat would plane beautifully.
Now a few comments on why we chose the 48 LRC. For the moment, I will ignore the additional dollars, but they were a consideration. The Admiral and I went into our search with a short list of "must haves". Some hers, mostly mine. Her primary "must haves" were, engine room access without going through the living area (I am a daily engine room person and she has trouble with a disorderly living space), galley up, cockpit for line handling, and a dinette. Mine were pilot house (the larger the better), a 12 volt DC boat, exposed inner hull bottom for entire propulsion systems, and stabilizers. We both agreed it had to be a Hatteras. We did look at two Defevers, just to confirm it had to be a Hatteras. The 48 LRC met all our needs and also put the master stateroom in the center of the boat (no more wave/hull slapping at night). I would have preferred 471 DD but the 48 only came with 453 DD. The Admiral would prefer full walk around decks, but the 48 maxed out the salon width instead. Everybody will have different priorities, but hopefully this insight of one owner's decision making will be of some assistance.
Pete