My comments are limited only to my bike, which is an 07SM 865 stock pistons, stock heads, TPUSA 813 cams, +3 Igniter, Chevy605LC pipes with medium G-pop tuneable baffles, Uni UP4229 pods, & carb tuning per my CVK carb tuning thread.
The above said, here are a few generalizations:
I found the NAGB & NBAD needles to be too erratic, no matter how they were shimmed. And they were far too lean in my bike without shims.
NBZT and N3RF are both good performance-oriented needles. Neither needed shims in my bike. Of the two needles, the NBZT runs a touch richer on the low end and the high end as compared to the N3RF. That is neither good nor bad, it is just different, and as such it effects the tuning at cruise & WOT.
Either of those needles can be made to work well, however the mains may be different, the pilots may be different, pilot screw settings may be different, yadda yadda.
I haven't yet tested the N3RL's, however I want to test 'em & see how they do. I suspect that the relative differences between it and the N3RF will be similar to that between the NBZY & NBZT.
The NBZY runs too lean in my bike without shims, however it is a decent performing needle. Just not as good in my bike IMO as the N3RF or NBZT.
Others will probably (ya know, it just doesn't seem natural typing that, as it does "prolly") have different experiences than mine. That is OK. This is just my experience.
One more thing about "profiling" needles; you really need to have an accurate, repeatable measuring device that reads to at least 4 decimal places. My craptastic HF digital caliper is very repeatable, however it only reads to 2 decimal places, which is quite inadequate for the close tolerances that needles have.
