The Oceanis 38 has been raising a lo of interest and some of its characteristics are revolutionary at least in what regards mass market boats, namely its interior.
Certainly the question is: Are the sail performance completely different and the amazing answer will be no. The Luffe 36.6 will be more rewarding sailing, almost for sure with an overall better performer specially upwind but in what cruising regards it will not be a very big difference with the advantage to the Oceanis in what regards sailing with much less heel and being much more stable and easy to sail downwind (and probably faster, given it the right amount of sail).
Regarding sail performance the nice hull of the Oceanis based on Open boat design give the impression that it is a very fast boat even in the category of performance boats. That is not the case and on a recent test with many cruisers on the water (light wind) the Oceanis was not even a match for a Varianta 37 (that is a downgraded and very inexpensive version of an Hanse) while the true performance boats like the Dehler 38 were incomparably better.
That has to due with weight the the poor running rigging, lesser control on the sails, less sail area (related with the boat RM). There is talk of a more sportive version. I doubt it because then the price of the boat would increase dramatically and what is going to make this a top seller boat is what the boat offers already for a very interesting price.
After having post this I have read the test on the Oceanis on the Voile and Voiliers magazine and some more information is available.
They measured these speeds:
With 22k trw at 50º of trw - 7K
With 20/25K trw at 150º of trw - 10K
with 17K trw at 135º of trw -8.5K
So it seems that as I have supposed the boat contrary to light wind performance has a very good downwind performance with strong wind and even upwind with enough wind the performance is very good for such a beamy boat.
But that very good downwind performance was done with full main and a big asymmetric spinnaker. It seems that they had a lot of fun sailing the boat and were also an experienced crew. What cruiser will carry a big asymmetric spinnaker with 22/25K on that boat? Certainly not alone and if with a crew it will have to be an experienced one.
With my boat (Comet 41 s) sailing alone with 25K TRW downwind typically I have a main with one or two reefs and a reefed genoa and even so I am doing about the same speeds they have measured here with a big asymmetric spinnaker. Of course I could went way faster I am sure, with a crew, even with another experienced sailor, with a better sailor than me or even without my wife
Bottom point, yes, that is a very good sailing boat for a mass main market cruiser with a very good stability downwind and able to carry a lot of sail. If sailed downwind with a lot of sail, a very fast boat, specially if we consider that it is not a performance boat.
Anyway a very stable and easy to sail boat with a good sailing performance even if sailed as most cruisers will sail it, offering a huge interior with a great layout and design quality and that is what most cruisers want and what the boat was designed for.
However it is good to remember that on that Norwegian sail test with the Luffe 3.6, even if not so specific about speeds and sailing points as the French one on the Oceanis, they say that the Luffe, also with Spinnaker will go at 9k with 17k of trw and that seems at least a comparable performance downwind with strong wind, but I bet the Oceanis will be more forgiving and easy to sail on those conditions.
I am sure that upwind and in light winds the performance of the Luffe will be considerably better. Again on the Luffe test they don't give much details but they say the boat will go upwind at over 6.5K and they refer that the test went with winds between 8 and 16K but they did not refer what was the wind speed for that boat speed neither the wind angle, but I am sure it was closer to the wind than the 50º where the Oceanis went at 7K with 22k wind.