ExRx.net

I'm probably nit-picking a bit (lol) but wouldnt an Upright Row be the opposite motion to a dip? If so, would that be a good choice for a super set? Its not really opposing muscles but its not the same muscles either, and it is opposing motion, so it should be ok? Really just wondering if there was a reason specifically not to do this (or if you specifically picked chins for a reason)...
Steve

I have found working opposing muscles is good when the exercises you choose do not share common stabilizers to a large degree.

The example of dips and chinups can be tough on the shoulder, which has to work hard in both exercises. So in this sense, you could be supersetting to work the shoulder stabilizers but this is not as effective in my opinion and can reduce performance on the target muscles as well as create a lot of fatigue and possible injury.

Biceps and Triceps often superset well because if there is shoulder stabilization involved, it is at a minimum so you can safely perform both movements back to back with no fatigue crossing over.

Leg Extensions and Leg Curls might be another example but the leg extensions usefulness is greatly limited in my opinion.

DB Chest Press (flat or decline) and DB Row(pulled to the lower stomach) are a good compound superset since they work all the muscles in the shoulder although there isnt really a join to balance out here but if you are going for cardio effect, then it is a good choice.

This leads me a reason to superset other than time; by supersetting, you are not preferentially training one muscle over another in terms of "freshness" in the workout so it can help maintain a higher degree of balance in addition to being faster and providing more cardio effect.