I'm 6' 0", but its hard to compare your height only because it has a lot to do with how long your torso is too. I'm pretty long-legged, so have a shorter torso, so I'd probably compare to an average guy of 5' 9" when sitting. You sorta have to judge how you compare to average.
But about the spoiler. I've got the '04 action package (with TRD
spoiler). I didn't like it too much at first, but I've come to like it a lot. For my height, whatever, it blocks a lot of the headlights behind me, so that with the tint means bright headlights behind are never a bother. I like the way it looks too. But I do think the Celi looks good without a spoiler too.