I used to run the 30's and they came with JJH needles straight from CPW.
I then got some N80F's and they were close, then finally got some N68A's and i found them to be Much better for my motor/mods and altitude.
Going off a standard JJH needle ( N80F needle was close), and comparing with other needles.
GJH: leaner taper, so leaner at ½-¾ throttle.
LJH: richer taper, so richer at ½-¾ throttle.
JJK: leaner diameter, so leaner towards ¼ throttle.
JJF: richer diameter, so richer towards ¼ throttle.
Bunch more.