I make a chambourcin wine every year and it makes both a wonderful rose and also a nice barrel-aged dry wine. The acid can run a little high for me since I'm not able to let them hang as long as a I want due to imminent frost in early October, but it doesn't seem to be any more tart than a Barbera or Tempranillo. The grapes usually get to about 21brix at my site.
As a table grape though, I'd give it a pass and reach for a catawba grape. Chambourcin grapes are big but light in flavor.