While I was not looking at the same models I can make a few general comments that were some of the "other" considerations for us.
Dealer. AF and EC were carried by a very strong dealer in my area with an excellent reputation (and my experience confirms it) The local Lance dealer was farther away, carried little inventory and didn't seem very interested in truck campers. I didn't feel good about working with them. Your experience may be different.
Price. The new Lances seemed very expensive. Maybe there was more room to negotiate than with the others. I didn't try.
Manufacturer. AF has a good reputation for supporting their products and that has been my experience. When I accidental "kicked" and broke a lite switch on the 2 months old camper I called them to see if I could buy a replacement. Instead, they had the dealer mail me a new switch for free. Lance is much farther away for us and seems to get more mixed reviews. EC has been in and out of bankruptcy several times. They may now have a stable home with Adventure but they didn't pick up the warranties on the older EC's. From a pure financial standpoint I understand but it didn't make me feel "good" about them.
Just my two cents.