The Call is a story that seems to get mixed reactions from fans and it's easy to see why. While the story is enjoyable its filled with enough plot holes to sink the titanic. But lets start with part 1.
It was neat seeing this Batman meet the futuristic Superman for the first time. It was also nice hearing Christopher McDonald voicing Superman as a throwback to Superman TAS and his role as Jor-El.
Apparently Superman suspects there's a traitor among the JLU and he brought in Terry to see if he can find out who it is. (as a mental note: THIS is the start of where "The Call" falls apart in terms of logic, but I'll cover that later in Part 2.)
The team consisting of JLU was pretty well put together I thought. Wonder Woman couldn't be used so Barda would replace her (we would see her later in JLU's "The Ties That Bind"), Green Lantern was be an interesting take on the character, Aquagirl proved to be the most likable and most interesting of them all (with the exception of Superman), Warhawk was a neat futuristic take on the Archetype Hawkman (who would later turn out to be "you know who's" son in JLU), there's also Micron who's an archetype of "The Atom". But he barely does anything so no need to worry about him. Terry's interactions with the new team were well thought out IMO, as was Terry's feeling of feeling unwelcome at The Metro Tower.
It's worth mentioning that the action sequences in the city are absolutely stellar for their time. We wouldn't see Action sequences this beautiful looking until Justice League season 2. Kudos to Adam Van Wyk, for the action sequences here.
The conclusion to part 1 comes when Warhawk seemingly blows up and his helmet smacks the Batjet's window, but he turns out alright later (which totally doesn't work given the explanation in part 2). Bruce looks at the scene in slow motion and discovers that Superman tried to kill Warhawk, and is the traitor (logically, this is where the story falls apart). At this point, I felt the "Superman gone rogue" had been done too many times in the DCAU, and this story wasn't something made this plot device feel special. The fact that Superman's last story in the DCAU "Legacy" used this same plot device didn't help much either.
The cliffhanger to this episode was a great one, when Bruce Wayne goes to get the kryptonite for Terry to use on Superman, as part 1 closes with Bruce's line to Terry, "Do whatever it takes, but make sure you stop him." It was a great cliffhanger to setup part 2, which unfortunately falls flat.