- For use with 75mm NN boots and does not accept cables. But you're an XCD skier, so you already knew that
- Aluminum base plate (Voile is 5052-H32 AL, Rotte is unknown spec)
- Steel bale. Based on the resistance of each to bending, I'd guess both steels are fairly hard but no spec is given for either.
- Rotte ST is lighter. Claimed weight is 370 grams for the ST, 440 grams for the HD.
- HD can accept a heel riser. ST has a simple fixed heel pad.
- ST can clamp duckbills less than 15mm. HD can accept 16-20mm bills.
- HD is grey and red. ST is black.
So besides all the tech specs, there are some details that really do make these bindings different in use.
First off the HDs have a really stiff action on the bale. It makes it hard to get in and out but I would imagine this tight fit eliminates any possible lash at the bale pivot. The ST has a really smooth action and it is very easy to enter and exit. Even the plastic pole push on the end of the bale works better.
The HDs have a bit tighter fit on the side of the duckbill as well. You might find some of the older boots even need to be ground down on the sides to fit. The ST provides a bit more clearance, which also aids in entry and exit but povides a slight bit of lash for side to side movement. When the bale is clamped tight, there really isn't much to notice.
The HD accepts the climbing wire. Although maybe a selling point, I've never used it personally. My thought is most skiing on plain pins won't actually use a climbing wire.
The hammer coat finish on the HD bale seems to chip fairly easily, and since there is no plastic for the pole push, the carbide tip on most poles will wear it and it will rust here. Maybe not much of a concern but rust does weaken parts, and maybe over time it could fail. The ST will rust as will if the finish is chipped but it's design lends itself to preserving the finish.
Overall, I think the Rotte ST is a nicer binding. It's easier to get in and out of and the bale design clamps down very securely to the duckbill. The slight lash at the wings is a performance detriment, but not a major concern for me.