But in fact you are saying that, I mean that the Oceanis 38 has almost the speed of a performance cruiser when you are saying that it will not be much slower than the Dehler 38, that one a performance cruiser.
Fact is that on the comparative test (Voile magazine) with all the boats of the water at the same time and weak to medium light wind the "cheap" Varianta 37 (an older Hanse hull) showed to be much faster than the Oceanis 38 and of course, the Dehler 38 much faster than the Varianta 37, even if the comparison is not fair since the Varaianta 37, like the Oceanis 37 is a family cruiser (main market) while the Dehler 38 is a performance cruiser.
I doubt it but maybe someone has the idea of racing the Oceanis 38 and then we can have the rating files where the differences will be clear. If nobody would take an Oceanis 38 for racing....that would be significant too, meaning it is not that fast
As said before and repeating again, It is always much easier to tune and increase a too small or "cheap" rig than a bad hull and keel. So, since I think the Oceanis 38 is such a good looking boat, both externally and especially internally, it is nice to read that the basics seems in place and adequately designed for good performance.
My own guess why it seems to perform good, at least when the small rig is not hampering it, is that Beneteau did not go down the Elan road, trying to make a planing performance cruiser, or cruiser and not going the full "Pogo" distance.
Using modern design input including double rudders but realising that a boat like this is not bought as a cruiser racer or for believing it will plane with cruising loads might perhaps be an explanation.
I personally would rather buy the Oceanis 38 and fix the rig instead of buying the comparatively traditionally designed Dehler with its missing hull windows. Or let's say it like this, do not show the Oceanis interior to your wife if you prefer another boat
On the other hand, a Dehler 38 with the Oceanis modern interior and hull windows and a super interesting package for our taste would be created. Partly it is already on the market but far too expensive. I am talking about the Solaris One 37.