The DGT North American is a good clock. When price is factored in, I would say that it is the best clock for the money. You should be able to get them in the area of $40-$45 if you look around.
Here are the disadvantages that I see:
(1) It lacks LEDs that allow you to know whose move it is from across the room. For me this is an important feature, as I like to get up and walk around the playing hall during my game to keep my mind fresh.
(2) It is very clumsy to reset the clock after a blitz game for another game. It is the same with all DGTs and I have never understood the purpose of this design.
(3) It is made of cheap plastic. Make sure you get a good one that is balanced on both sides of the levers. It is very annoying when the levers require different pressure to get pressed down.
As someone stated above, the DGT Easy is a piece of crap. The TD at my local chess club went cheap and ordered them for the club and they are the worst clocks I have ever used, much worse than the Excalibur. Compared to the DGT Easy, the Excalibur is a Chronos.
The worst thing about the DGT Easy is they make a loud click-clack sound when the levers are pressed that makes it impossible to play a game of speed chess in a corner of the club without complaints while a tournament is going on.
The DGT 960 and Easy are horrible. Don't buy them.