The Wing Keel on production boats like the newer Catalina 30
and the Ericsons are for the advantage of a shallow draft
. They will not point better than the deeper keel boats and are probably less stable.
On the Americas Cup racing
boats however, the wing is added to the deep keel. The keel wasn't shortened at all. This is why the Australian Boat (with deep winged keel) in 1983 kicked the crap out of the US boat (deep keel no wing) and Dennis Conner to take the Cup which the US had held onto for like 130 plus years.
Also, lots of weight was added to the wing which was great since it was located near the bottom of an already deep keel.
I said they kicked the crap out of the US boat, but it was actually a bit closer than that due to mistakes