As Chad Ward says in his book "An Edge in the Kitchen" : "Unless you are planning to jack up your car or pry open doors with your chef's knife, the tang plays little or no role in its strength and durability. It does help establish the balance and feel of the knife, but as we discussed with bolsters, there are many ways to balance the knife. With modern manufacturing methods it is inexpensive to place riveted handle slabs on a full tang. A full tang is a manufacturing choice and a stylistic choice. If you like them, great, have at it. Just keep in mind that any reasonably sized tang that extends at least two thirds of the way into the handle will be fine.
If you insist on a full tang, you'll miss out on a huge array of truly spectacular knives. Want to spend a couple of thousand dollars on a custom made Japanese yanagiba (sashimi knife) hand forged by a master craftsman with a 700 year history of knife making behind him? Oops, can't do it, the yanagiba has a stick tang. Want a reasonably priced chef's knife that won't expire if it finds its way into the dishwasher every once in a while. Sorry. Hidden tang. You're out of luck.
The tang should be pretty far down on your list of things to look for when choosing a knife or two to outfit your kitchen."
Personally: I agree with Chad - The tang should be pretty far down on your list of things to look for when choosing a knife or two to outfit your kitchen