The Microcender range are superior to a standard toothed jammer like the Basic for backup because they are much kinder to the rope under a shock load (which is a given as it is being used as a towed backup device) - they tend to slide a little first rather than rupture the rope sheath. A Troll/ISC Rocker or equivalent towed backup device is probably even better.
Having pretty much every backup device ever made at my disposal, I tend to opt for the Microtraxion. The advantages of a microcender etc are purely theoretical unless you plan on long falls right below the anchor. If I want a second system I use a Kong back-up on short lanyard. IMHO it's the best of the rocker derivatives for climbing contexts.
I think John Middendorf was instrumental in the design of the rescucender non-toothed cams?
Those Rock Exotica devices were developed from the Gibb's ascender, which I'd guess long pre-dates John. Petzl bought them ~15 years ago.
Just revisiting this because I want to revisit my shunting setup(s) for the spring.
JB - with a Microtraxion and your Kong Back-Up setup, are both devices on the same rope (or are you using a doubled rope)? And what sort of lanyard is the Back-Up attached with?
I've generally been using 2x Microtraxions with the upper one attached by elastic to a sling round my shoulders to keep it pulled up. I've experimented with a top MT along with a GriGri below, but its a pain in the arse to keep pulling through, so generally put the GriGri on my harness if I might need to go down at some point.
