The main difference between what you have been flying and the long body is how it sits on the ground.
The following is from Trey Hughes Pilot review of the M20R. "When we talk about landings in the Ovation or any of the new generation long body Mooneys (M20M, M20R or M20S) we must talk about the landing attitude. As I mentioned earlier, the long bodies sit with about a positive 4.5 degrees pitch attitude on the ground. Pilots moving into the newer aircraft from one of the shorter length Mooneys (M20K or earlier) will immediately notice this difference when they first sit in the cockpit. Now thinking about sight picture and pitch attitude during the flare for landing, most aircraft will need about + 5-degrees during the round out to keep the nose wheel off the runway until the mains are on. This works quite well for all the Mooneys except the Ovation, Eagle or Bravo. With an almost 5-degree nose up attitude sitting level, the pitch attitude is going to need to be higher during landing in order to land on the main wheels before the nose. One of the biggest transition problems I have found for pilots moving into these long Mooneys is the landing – more specifically, landing on the nose first or all three simultaneously. Either action can quickly lead to a porpoise and the outcome of this isn't very pretty. Pilot must develop a different sight picture when landing these new Mooneys. Where 5-degrees worked before, 8-degrees is necessary now. This just takes practice and the help of a competent instructor familiar with long-body Mooneys.
As with all Mooneys, airspeed control during the final approach is key. Fly too fast and the airplane will float on a cushion of air forever. "
Also you will find that if your landing speed is 75 Kts at gross it needs to be about 5 Kts less when 300 lbs less than gross. If you are on airspeed with full flaps you will have max trim up which will set you up nicely for a landing with very little flare required. Be prepared for significant control input in a go around until you take out the trim. Basically your sight picture will be the horizon as you touch down.