Now, before people start complaining, I'm pretty sure the reason FELD changed Superman to this is because the DC trucks are actually now sponsored by DC's parent company, Warner Bros., not directly to DC. Similar to why Batman also received a makeover last year, Warner Bros. wanted their trucks to resemble the likeness of recent movies.
So before this becomes another round of "why'd they change it?", it's most likely because there are still fans of the Superman style truck and they may not have been able to keep the truck around otherwise.
The absence of a cape might have something to do with a cape being used on another TBA (in the United States?) superhero truck, but all we can do at this point is speculate.
All in all, the overall design of the truck isn't too bad, I think the render just makes the truck look more shiny than it will be. Yes, it's a standard mid-2000's Ford F150, but looking past the simplicity, the paintjob fits the modern Superman concept, and if it's true FELD was unable to use a cape, there's not much that can be done with a Superman style truck without making it look ridiculous (3D hair ), so they figured the best thing they could do is leave it the way it is.
TL;DR This time FELD most likely has a good justification for their choice as opposed to what happened with El Diablo.
It might just be me, and I might be looking into it a bit too much, but I feel like people are starting to become more prone to complaining no matter what choice FELD makes (I'm not saying that El Diablo wasn't a bad idea).