Basically the same hull minus a foot or so of topsides, though the J/29 keel is a little deeper at 5.6' vs 5.25' for J/30. You'll have to work harder to keep your new boat flat. Also since you now will actually go below, manage your cruising gear so you don't accumulate excess weight. There was once a member of our fleet who was some speed issues. On board we found a full set of Corelle plates, bowls and stainless flatware plus a copy of Chapman's. You'll want to leave those at home when you are racing.
