They're very comparable...to the point that you'd have to hear each one in your system to determine which you prefer.
Each has the qualities you seek.
The Silkworm is more flexible because it's in a thinner jacket (actually just techflex over the conductors...unless something has changed since I owned them).
The GG interconnects are also flexible, but because they use a larger jacket, they have less flexibility at the junction between the cable and the connectors, so they won't bend quite as close to the connectors as will the Silkworms.
Each has the qualities you seek.
The Silkworm is more flexible because it's in a thinner jacket (actually just techflex over the conductors...unless something has changed since I owned them).
The GG interconnects are also flexible, but because they use a larger jacket, they have less flexibility at the junction between the cable and the connectors, so they won't bend quite as close to the connectors as will the Silkworms.