From what I can see. the APEX will be your best choice. It sleeps 6 in comfort. It weighs in with enough room left over for you to load it for camping. 4370lb dry is too heavy for the Explorer. You will be over that 5000lb cap in a New York minute. You will only have 630lb to load camping stuff for 6 people. Plus. Remember every pound you put in the Explorer over the 150lb driver. comes off the tow capacity.
The 3300lb APEX leaves you 1700lb before you top the Explorer's tow capacity. Plus the 4500lb GVWR is still under the capacity of the Ex. to be safely UNDER your capacities. The APEX is a good fit.
Something else to think about. The Apex is made of AZDEL. A modern State of the Art ultra lightweight composite, That is 50% stronger than laminate, 50% lighter, and has a 50% higher insulation R value than laminate, or aluminum. AZDEL also will NOT rot. In truth. The Apex is one of the better built TTs on the market. The slide out mechs are made by Lippert. Top of the line in slide out technology.
I have an Apex, and after 4 camping seasons. It still looks new, and has given no problems.