The J/105 is one of the most stable boats sailing downwind I steered. I raced a few years at the helm of one. In coastal races up to 200 miles downwind with winds up to 35 knots and I steered with two fingers, completely stable boat, flying over the waves at 16 knots without a single broach.
With all our focus on the J 105's downwind capabilities, we should not overlook that it goes upwind quite nicely as well, particularly if you have the right crew weight on the rail. Most of my time spent on the boats has been in the bow position, and looking aft I would see the helmsman typically steering upwind with a thumb and two fingers on the wheel, even in moderate breeze.
Interestingly, while I consider the J 105 to be a rather wet boat, the raised cockpit combing does a good job of channeling the water coming across the deck aft to the stern, so if you happen to be in the cockpit (preferably behind a dodger), the boat is actually quite dry. So, for cruising I suspect it would be rather comfortable (I've never cruised one and never been aboard a J 105 that had the dodger rigged) and dry.
One more story - for the 2008 Coastal Cup Race, from San Francisco to Santa Barbara, California (350mi / 560km), we encountered breeze in the 30-40 knot range off the infamous Point Conception where we ended up going to bare poles for a time, while still doing about 8 knots downwind, in very nasty cross-seas (one other J 105 was dismasted nearby). When things calmed down we carried the .75 the rest of the way averaging 13-14 knots, until we were finally forced to do a letter-box drop just north of Santa Barbara when the late afternoon offshore breeze kicked back up into the 30s, and we were screaming along with the foredeck covered in water, in the high teens. I was on the wheel at the time and can remember seeing the eerie glow of the bow lights shining under the water coming over the bow, wondering how were were going to slow down and keep the rig on the boat.
Needless to say, we did get the kite down only to have the breeze die to nothing within just a couple miles of the finish (in typical Coastal Cup fashion). We spent the night bobbing up and down within site of the Santa Barbara pier and the finish line, finally finishing on the early morning offshore.
Just one of many fond J 105 racing memories.