Most of the other chips don't seem to offer much improvement, and some actually have disabled safety features. If I remember correctly, one has knock retard completely disabled. You won't lose timing, but your engine will just keep detonating away until it's totally dead. You're probably better off saving the money, and using it toward the Ultimate and its prerequisite mods a litlte further down the road.
The Ultimate is the only one that uses a 3-bar MAP sensor. Stock uses 2-bar, which is -15 to 15psi. The 3-bar lets it see (and adjust for) up to 30psi. With any other chip, it can't tell if you're at 15psi or 35psi. It all looks the same to a 2-bar chip. Obviously that leads to fueling issues, which leads to knock and broken parts...
Either get an Ultimate and the supporting parts, or have your stock chip reburned with a tweaked program (EGR disable, more knock retard, IC pump always on, etc.). Remember that you need to have your truck in perfect running order before you put the Ultimate in. You'll be amazed at all the stuff that Datamaster shows you, that you never even knew was wrong.