I agree with terrapinj that the Stone Dayman IPA was OK. Initially I thought it was great, but after the excitement faded the flaws started to shine through, particularly as the beer warmed.
In my opinion too much acid came out of the coffee, possibly due to brewing method. It almost tasted of burnt coffee which is probably why you get the sense it was an overly dark roasted bean, even that stale taste.
Personally though, I think you could do a dark roast successfully in an IPA but it would have to be cold brewed to avoid the astringent and even stale/burnt coffee taste.
I plan to make a similar IPA but with coldbrewed coffee. To cold brew, I take about 1.25lbs of coarse, freshly ground coffee beans and steep for 12-16 hours in fresh, filtered drinking water - about 9 cups. The longer you steep, the more acidity you get out of the beans in my experience and I tend to prefer my cold brew steeped 14-16 hours (usually 14). Can I really taste the difference? I think so... But I could just be convincing myself. I definitely feel that cold brew allows you to get full coffee flavor with a more smooth finish and decreased acidity overall compared to hot brewing.
When brewed this way you can have a regular strength cup of coffee at 3:1 water:coffee ratio or espresso at 1:1 ratio. I usually mix my coffee extract with hot water from my water bar. I would experiment with coffee "extract" addition when racking to the bottling bucket and just do a little at a time until you get where you want with the coffee flavor.