yeah, I love it too. I own the series in english on vhs and in japanese on dvd. I've got the movie in english and japanese as well. If you are into that, you should look into samurai champloo as well.
As for the jkd, it's not that realistic, IMO.
1. it's an anime.
2. you never see spike trap or even clinch, nor do you see anything WCesque - unless he did sbg jkd. he uses a lot of high kicks and spinning kicks. you see him throw a few punches when he fights Ed's dad(hard luck woman?) and he uses in elbow in his fight in the casino (honky tonk woman). There are other punches to (the fight in the alley in Jupiter Jazz), but mainly kicks.
3. there are no real references to jkd in the series, if I remember correctly. He does have an affinity for a guy named Bruise Lee, but it's never revealed that he studies his style. However, in Waltz for Venus, he does say "be like water". There are a few other references to lee also, posters and such, and the character reminiscent of kareem abdul jabaar whom spike fought.
He may not have trained JKD. I think we just assume he did because of the "be like water" reference and all of the references to lee.
i'm nobody...i'm nobody. i'm a tramp, a bum, a hobo... a boxcar and a jug of wine... but i'm a straight razor if you get to close to me.
-Charles Manson
I will punch, kick, choke, throw or joint manipulate any nationality equally without predjudice.
- Shonie Carter