I wouldn't pick one boat over another because of a water maker, especially not when the 4600 holds about 200 gallons. Unless it was the same price or so close it wasn't significant.

BUT, I would take the 4500 over the 4600 for a lot of other reasons. Forward cockpit and forward galley being two of them. In addition, the 4600 is an old boat. 4500 is brand new. You'll have much more up to date systems on the 4500 as well. Not to mention electric davits vs the manual davits on the 4600.

So if you are actually considering it for JUST the watermaker, then I'd say go for it because of all the other benefits.