.. And the rating, isn't it based on past performance in races? I hope that I would have the chance someday "to meet" an Oceanis 38 somewhere in the Med and to check our performance in the same conditions.
No, the rating is attributed measuring the boat dimensions and trough a computer program that predicts the performance. Sometimes the RM is also measured (in some systems) to give a more accurate prediction. Those results can be corrected by the results in races but the alterations are minimal.
Through a very sophisticated program the prediction speeds are very accurate. The boat designer through the computer programs that use to design the boat is also able to make very accurate predictions about the boat speed.
You can ask to the Luffe shipyard a Polar speed of the boat and we can compare those predicted speeds with the predicted speeds of other cruising boats.
Regarding the Luffe 37 its Swedish rating (LYS) is 1.23. a Hanse 375 has 1.26, a Salona 37 1.30 a Grand Soleil 37 has 1.29, a Hanse 355 has 1.23, Salona 38 has 1.32, a Elan 310 has 1.22 a Arcona 340 has 1.30.
The bigger the number the faster the boat. The Luffe 37 was a very fast boat when in was designed (the hull) in the late 70's. Now a mass market good 35ft/36ft is faster.
I am quite sure that the Oceanis 38 will be faster and will have a ratting higher than the one of a Hanse 355.
Speed is not everything in a boat and Luffe are great boats with high quality building and interior. I am sure the Luffe 37.09 is a very agreeable boat to sail and a very nice classic Yacht but if you are buying it because it is a performance fast 37ft cruising boat...then you are wrong.