Whether it's power generation or efficiency I can't say but I'm definitely pokier on my NWT than on a standard diamond-frame bike.  I averaged only 10-11 mph on level ground this summer on the NWT, where my diamond frame bike "likes" to go more like 13-14 mph on the same terrain.  FWIW, my NWT has had road (drop) bars since new, and also the hubs on the upright are of better quality than those on the NWT so that's also a factor to be considered.

I do have the NWT set up to put me in a relatively "aggressive" posture, more forward-leaning than most other tourists.  The bars are actually slightly below the level of the seat, with a relatively long reach (goes with my long torso and orangutan arms, I guess...)

Make an annual New Year's Day habit / routine of pulling the seat post, seat mast, and handlebar mast and giving them a light buff with fine steel wool, then greasing them before reassembly.  That'll pretty well stop their tendency of getting stuck, unless you ride a lot in really wet conditions.

Hi Brent, a late addition to this thread. My wife and I have four Bike Fridays. Two custom built 20” wheeled New World Tourists, and two 16” wheeled Tikits bought off the shelf.

We’ve made good use of them over the years. For example, we used the NWTs to tour around Japan in combination with train travel. They well, though in hindsight, the Tikits would have been easier to manage getting on/off trains. 

I’ve done some substantial, solo fully loaded tours on my NWT in rural Australia and New Zealand. I’ve covered up to 140km per day on the BF with a heavy load in hilly country. It tours on sealed roads almost as good as my 26” wheeled heavy duty Thorn Sherpa. The only difference is that there’s a bit more flex in the BF, especially in the rear rack. 

That said, unless you are going to make a lot of use of the folding function reasonably often, don’t get a folder. There’s a weight/cost penalty, and folding bikes are hard on cables.

I’ve used my Tikit quite a lot for local bus travel. Not fully loaded, just taking a few things to visit my son who lives about 3 hours bus ride away. It’s so easy to cycle to the bus station, fold, bag and load the bike as luggage. And reverse the process ar the other end. It’s saved me a lot of money in taxis.

For travel on planes, folding bikes packed into wheeled suitcases, are wonderful compared to the nightmare of boxed bikes.

So in summary, I highly commend Bike Fridays. But I also recommend having a full sized touring bike for times when you do not need to fold and pack the bike on your.

I should mention I know nothing about Dahons, but I do also have a Taiwanese made KHS folding bike. 20” wheels. Excellent bike.

And I also have a Pacific Reach 20” full suspension folding bike. Taiwanese made. It’s also excellent. My son and I rode around Taiwan on these bikes. The journal is here on CycleBlaze. 

Thank you for the input.

Yes, I agree with having a full-sized bike (I have two). I generally use full-sized and simply plan my tours to fly mostly on a Canadian airline (reasonable fees for bikes) and use the Dahon when not, which is not that often.