I'm sure this horse has been beaten but...
 

Would JL Rubi suspension be a "worth it" upgrade for my old 2008 JKU (sport) for 100 bucks? Would it even fit? Mostly a daily driver but I would like to start having a little trail fun again.

JL has a softer spring rate from what I've seen so no, it would not work for you.

Thank you! Will keep an eye open for a JK Rubi set :)

I don't think it's worthwhile at all. If you had a 2dr, you could benefit from JKUR springs, but putting those on a non-rubi JKU isn't worthwhile at all. You'd be better off getting a 1" spacer puck set for $50 or whatnot

I've had a $100 takeoff JKU, hard top, Rubicon suspension on my 2 dr sport for the past 7 years. I gained almost 2" and a better ride. I still like it