I have to agree with Yotphix. In my opinion there is no correct answer to this question. Assuming that the install was done correctly there are advantages to each system:
Keel stepped advantages:
- easier to for racing
-More solid base. (this one is questionable)
-Able to change rigging
w/o a crane
Keel stepped disadvantages:
-bottom of mast prone to corrosion
-when dismasted may rip out part of deck
Deck Stepped Advantages:
-Able to lower/raise mast w/o a crane
-won't tear up cabin when dismasted
-cheaper (for builder)
Deck stepped Disadvantages:
-requires compression post
-may have problems is deck softens
-extra connection point to boat.
Please feel free to add advantages or disadvantages.
I think that each of the systems has good points and bad. I can see where a particuilar use of the boat might be more advantageous than another (i.e a race
boat with a bendy rig is better able to tune the rig with a keel stepped mast or a local cruiser might want to have a tabernacle mast that they can use with an electric winch
to go under bridges)
In my opinion it all comes down to a matter of personal preference.