These two boats are in direct concurrency on this main market segment. They are similar in the concept, yet different:
The Bavaria weights 9800kg and the Jeanneau 7860kg but probably the Bavaria is way faster because it compensates the superior weight with a lot more sail area. The SA/D for both boats are 19.6 for the Bavaria and 17.2 to the Jeanneau.
Curiously, since the weight of the boat has many times relation with the price, the Bavaria is substantially less expensive : 134 900 to 154 900 euros.
Everybody that sailed the Bavaria, including the testers from Yacht magazine said the boat, like its big sister, the 46, sailed very well, but I don't like the low ballast displacement ratio that is similar to the one used in the Benetau Oceanis line. Regarding the jeanneau they did not disclosed the ballast and I don't mean on the official page but to nobody. Not even on the Jeanneau owners forum you can find it and when that happens it is normally a good sign.
In fact the Jeanneau 409 had a good B/D for the type of boat (and you can find the boat ballast on the net) and had on the basic version (with less sail) 78.9m2 of sail and a lot more (with the same ballast) on the performance version. The 44.1DS has the same weight but only 66.7m2 and such a big difference in sail area on the same hull leads to suppose a smaller RM and therefore a smaller B/D.
Between the two I would chose clearly the 42 Vision, not only is substantially less expensive as with almost more 2 tons it will be a more seaworthy boat with a feel of a bigger boat without being less fast.
But I maintain that cruisers are being mislead with this type of boats. Cruisers tend to assume these boats safer and more seaworthy that boats that looks more sportive and it is just the opposite.
It is the case regarding the Jeanneau 409 and the 411ds (assuming I am right about the ballast and the relation with the sail area) and with the Vision 42 Vision and the Bavaria 40 cruiser that has a significantly bigger B/D ratio with a similar keel and similar draft. These kind of boats offer also more windage and a more narrow and difficult passage from the cockpit to the mast.
Sometimes they are not even better in storage space or interior surface space but only in what regards interior volume. They provide more standing height and more interior light. That can be a enough reason to buy one if the interior of the boat is by far the more used commodity. They give very good liveaboard boats or weekend houses in the marina and even so they provide a decent and in the case of the Bavaria, looking at the SA/D, a good sailing performance.
from the Yacht magazine test:
Familienzuwachs: Bavaria 42 Vision - Yacht TV - Segel Videos von Europas größtem Yacht Magazin