If you passed me on one of my DFs you wouldn't say DFs are slow up hill. Yet when you pass me on my 'bent ALL 'bents are slow up hill.
I've always been slow uphill and always will be on anything without a motor, DF or 'bent! On the other hand I have had riders nearly kill themselves trying to catch me on the level into a headwind, while I was cruising, and flog themselves down hill while I'm freewheeling.
A 'bent is was it is. I've ridden with fit DFers who disappear up hills and don't wait at the top, I catch them on the way down or on the flat later.
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.