Somebody gave me the first two seasons but after watching both, I wasn't inspired enough to pursue additional seasons. The storyline sounded so interesting, so promising. Sadly, I just couldn't be lured back.
None of the characters had an appeal to me either. I'm not a big watcher of shows with seasons, I prefer movies but to name one example I thought was good was Schitts creek. I pretty much looked forward to each character. And that show didn't have the promise of aliens or abducted people returned to Earth years later with no memory. Schitts Creek just had an honest gay, a crazy lady named Moira or a man that once said "Behold the Mermaid".
But I just didn't get attached to anything much about the 4400 and a couple of the characters were flat out outrageus like the man that guarded the mentally ill girl. Well, maybe the show got better. I will not know.