The three differences between them are the length of the cable, USB-C Power Delivery (PD) profile, and USB transfer speed.
The longer 60W cable supports USB Power Delivery profile 4 (5V/2A, 12V, and 20V/3A) while the shorter 100W cable supports USB PD profile 5 (5V/2A, 12V, 20V/5A).
Sadly, the 60W cable only supports USB 2.0 speed of up to 500Mbps while the 100W cable supports USB 3.1 Gen 2 speed of up to 10Gbps.
Both cables are made from ultra-rugged ballistic nylon housed in a thick protective fire-resistant PVC jacket. The cable comes with reinforced RF shielding to prevent interferences.
Since the 60W cable is 1.5m in length, it comes with a vulcanized LSR silicone cable tie which is similar to that from the Nomad Universal Cable (1.5m).
I bought the 1m/100W Nomad USB-C Cable cable from iStudio at Siam Paragon for TH฿1,190 (S$50).
Nomad online store is selling it for US$34.95 (S$49), but shipping to Singapore is expensive at an additional US$13.75 (S$19). Even though there is a 20% discount with the promo code EARLYBIRD for this upcoming Black Friday, it is still more expensive.