This is a great way to introduce them to the verse, especially if they have resisted watching the show or even haven't heard of it before. I know my family would love Firefly & Serenity but they just don't have the time to watch the show first. Think of this as a 2 hour time commitment versus a 14 hour one. And not only is it shorter, it's also cheaper to buy than a $30-$40 box set of the show.
Anyway I just think Serenity would make a great gift - and hey if you can afford it, why don't you make a Firefly/Serenity gift package and buy the box set too?