I am purchasing a stem for a vintage sport touring bicycle and am trying to discern the difference between a Nitto Technomic NTC-150 and the more expensive Nitto Pearl.

Assuming a clamp size of 25.4mm, both appear to be 150mm in height, made of forged aluminum, angled at 71º, even in weight, and have the same style of clamp—though differ significantly in price.

Is there a substantial difference in the finish (it is difficult to tell in pictures on the web)? Does it all come down to the Pearl's NJS approval (though this would be moot if the clamp was 26mm)? What reason would there be to choose the Pearl?

Any assistance in distinguishing between the two would be dearly appreciated.