KP Options and Harmony and Zephyr interchangeables are great. They're not too spendy. Some parts might have 'issues' or 'defects'...however, KP is quick to replace the part, no fuss no muss for you. Just call them. The part is delivered to your door asap...no questions asked, no returning defective parts.
Addi Clicks are great, lifetime guarantee. But they are costly.
You could order KP Options AND
Harmony sets for the price of an Addi Clicks set.
I own full sets of Options NP and Harmony, and some Zephyr tips. Zephyrs knit like Harmony's IMO.
I have Boye Needlemaster interchangeables, and Denise interchangeables. I don't use either anymore.
I use KP Options & Harmony 24%, and Addi Clicks for 76% of my knitting.
KP Options and Harmony are very pointy tips. Can split yarn.
Can hurt fingertips if you 'push' the needle.
Addi Clicks are rounder tips, however, they don't split yarn, and they never hurt my fingertips. I use them most of the time, unless I need pointy tips for cables or tight places like the Textured Pattern Stitch of the Clasica Coat! KP Options made it so easy!