I think there are a couple of other factors relating to the type of hills too.
In Mallorca a couple of years when I took my Speedmachine on a cycling camp about a week after I got it (

, I found that I didn't have the confidence to even attempt to keep up with other riders (on road bikes) on the long hills (5 - 10km) or the steep ones (>10%), partly because of the fear of exhausting my leg muscles and coming to a dead stop. This would not be a factor on a road bike (and much less on the trike) as I know I can slack off and ride slowly until my muscles recover.
On the shorter hills, and the longer gentler ones as I got fitter, I had no problem keeping up and would usually accelerate over the top to hit the downhill first to save the bother of getting around the slow descenders - and lets admit, they're all slow when you're on a 'bent
I was riding with the same riders that I would have been with if I'd been on a road bike.
For any one who knows Mallorca, the Orient climb is fine on a 'bent and so is the climb to Lluc, Soller's nice but the descent is a bit hairy with X-hatching on the corners, but the Puig is a bugger although worth it for the fabulous descent back to Lluc.