There are more than subtle differences between the old "Davy Crockett" portable (skinny legs) and the new "Trek" portable (short legs, with a stand option). The Trek has a sliding inner heat shield/diffuser while the DC's have a fixed heat shield. Some of the DC's came standard with a perforated grease tray, although it can be added to either DC or Trek.
Also, those skinny legs fold up into a handle. If I was going to have to carry that 60+ pound portable grill more than 10', I think I'd appreciate the integral handle. Those skinny legs can also be used at ground level, although you'll need a short stool (or bucket) to sit on to tend it, while the Trek short legs really do require a table (truck bed or insulated picnic table) or the optional stand to use. The very early DC's maybe didn't have wifi and phone interface, but the later ones did.
If any of these features are more or less important to you, you may want to choose just which portable GMG you get. But all Green Mountain products seem well-built and have a loyal following here.