We have found the J-30 to be very satisfactory for cruising. Certainly consider getting a Life Sling and installing a tiller pilot if the boat doesn't have them already.
The fractional rig and jiffy reefing allow you to readily depower if required. You'll stay pretty dry when cruising if you drop to the #3 when the wind is above 15-18 Kn.
I think the limitation on the J-30 as a cruiser is the difficulty in providing an adequate bimini.
