My order finally arrived today, after a three month wait, and I've got to say, it was well worth the wait.
The rubber-capped spikes in particular, use the best-of-the-best materials, such as hardened stainless steel for the spikes, and very solid-fitting rubber caps. That's a detail that's often missing from other after-market spiked feet. These Gitzos' will probably outlive the tripod. (Gitzo GSF30s spiked feet for 2-series tripods.) One pair will be mounted on my 2-series Gitzo GT-2545T Traveller, and the other set is for my 2-series Gitzo Mountaineer GT-2542.
I also received a pair of the Gitzo column-mounted spirit-levels; one for my 1-series Mountaineer GT-1542) , and the other for my 2-series Mountaineer,(GT-2542) Very happy with this purchase