I have both rims and they are extremely similar. The HED's are matte black and (unless he has some NOS) feature etched graphics. The Pacenti's are glossy black with removable stickers. The SL23's are a bit more 'tubeless ready' right out of the box (if you are going that route), but are a major pain to mount tires/tubes on if you are not.
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"The older you do get, the more rules they're gonna try to get you to follow. You just gotta keep livin', man, L-I-V-I-N." - Wooderson
'14 carbon Synapse - '12 CAAD 10 5 - '99 Gary Fisher Big Sur