I have been using the Marker Dukes as my go to binding for the past 4 (or 5?) seasons, and they are exactly what you think they are. A solid inbounds downhill binding with ability to take you into the slackcountry and to a lesser extent - backcountry.
Up until last year, I was using the Dukes exclusively for slack/backcountry travel and they got me everywhere I wanted to go - albeit, quite tired at the end of the day. It wasn't until last year when I got a touring set up with Dynafit's that I truly realized how bad the Dukes really are when it comes to travelling in the backcountry. The pivot point is too far forward - taking away from your stride, they are really heavy and bulky, making big climbs, breaking trail, long traverses, and big travel days a chore. I would not recommend these bindings if you are considering any extensive backcountry travel. For slackcountry though - they are still my go to, and they are, for the most part - the main binding I use inbounds as well.
Besides their downfalls for the uphill in a true backcountry setting, I have broken the Duke 4 different ways over the past 4 years. It seams like I can always find a new way to break these things. I am 6'1", 190lbs, and very aggressive on my skis so I may be the exception. I have many, many friends who have been using the Duke just as long as I have with zero problems (besides the toe riser busting, but that seams to be inevitable). So if you are tall, heavy, and aggressive - expect to break these things. The fun part? You never know how you're going to break them, every time is an adventure! hahaha. (note: I have yet to find a binding I can not break, so take this with a grain of salt)
In the end - solid inbounds/slack binding. Stay out of the park, try to find a lighter set up for big days in the backcountry. I recommend anyone with any interest in getting into touring to start with these puppies and explore your local mountains.