Having a poke around the new constraint system in h16 and so far so good. Came across the constraint visualisation type, and thought it sounded handy, however I can't get it to actually do anything.

I have a vague memory of seeing some nice tag style visualisations for constraints, but haven't been able to find anything on it in the docs.

Wondering if anyone had given the constraint visualiser a whirl and if it was indeed the visualisation I'm looking for

Enable the visualizer and set the Display flag on the constraint CHOP nodes.
You should see small axis tags being rendered in the viewport.
At first it was the only way to vizuslize the tranform frames in the viewport but now you can also rely on the tranform manipulator on selected CHOP nodes.

Cheers, Guillaume! I swear I tried that (being the obvious thing to try), but guess not. That was what I was thinking of with regards to tags.

The constraint visualiser is actually a lot cooler than I first thought; by naming the displayed nodes and setting the the visualiser so it only display on “selection” you can get a good idea of what constraints the node has, which is pretty nice

Is there any way to see constraint relationships in the network view? Turning on dependency view shows that there is a dependency, but gives no indication as to the nature of the dependency (it could a channel reference not a constraint). Is there anything I'm missing? We're currently doing some rigging and were keen get in on all the fancy new tools, but the lack of a visual link defining constraints in the network view is proving a little disconcerting. It may just be a matter of getting used to new things.

(OT but just discovered the link triangles showing references and dependencies when you have "show dependencies

There's a constraint badge and a link to the constraint path.
I do find the references showed when you RMB on the link triangles could also show how the reference is pulled.