Not the ballast...
Water ballast doesn't make the boat tender, it's the location of the ballast.Remember the old riddle, "What weighs more, a ton of feathers or a ton of lead"? A ton of water is still a ton of weight.Almost all cruising sailboats have a deep keel, with the ballast weight down low, in the keel. A water ballast boat has the ballast weight much higher, up inside the hull. This isn't a bad thing; all the really big commercial boats (sail and power) have ballast weight (usually cargo) inside the hull.But the distance from the balance point (the 'moment arm') is a simple lever; the greater the distance (the deeper keel, or the deeper the ballast -- i.e., in a bulb keel), the more effective it is in resisting heeling (in resisting the effort of the wind to push the boat over).Keel boats out-perform water ballast boats in nearly every way (water ballast boats are better at shallow running and beaching). Water ballast boats haven't been around long enough to determine how long they will last(I'm talking decades, not years). I personally would think twice about buying a water ballast boat that is more than 5 years old, but that's because I don't know what shape it might be in another 5 or 10 years.There is only one reason to buy a water ballast boat: to trailer. If you don't plan to trailer it, don't buy a water ballast boat. For some (including me), trailering ability is more important than performance.There is only one type of boat I know that does not sacrifice performance for trailing capability: the trimaran. But you do sacrifice interior space, and trimarans are very expensive compared to keel and water-ballast boats.Another good compromise is the trailerable boat with a heavy (up to 600 lb) swing keel. That is the Hunter 212, the Catalina 22, and Ken Hankinson's Ensenada (if you want to build your own sailboat).