I have those brake calipers (stock). They function well enough with Kool Stop pads. I think the weight is actually pretty good too. But I'll admit that I keep an eye open for a pair of Ultegra's to match the rest of my build.
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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