One of the things I found with internally geared hubs was their weight. They bloody things are heavy, especially relative to regular sprockets. Ride feel is affected by wheel weight. The lighter the wheels, the more lively the ride, aside from the drag extra weight around thing. The gear ratio jump is also disturbing. Most of the internally geared hubs are made for people who commute on bikes, so flat city scapes and traffic is really what they where set up for. Belt driven ones are especially targeted for that market (no grease on you pant legs). To get a truly nicely performing internally geared hub, you have to step up to the likes of a Rohloff hub, really nice German hub made from exoplanetary materials, or so it seems from its jaw dropping price.
On the Srurmey Archer hubs, I had a couple of different sprockets for the hub, they where cheap ~$6 each and changed in a few minutes. I swapped if it was really hilly in the area. I just didn't find the hub a truly satisfying experience. So I only retained it for my novelty antique folder. I switched my full sized folder, the Dahon Espresso back to a standard setup and it transformed the bike from oinking hog to a nice riding unit. There are lots of different folders out there, they are pretty much equipped dismally with the lowest cost components they can find that look cool. When I go to Afrikaburn in South Africa, I volunteer to fix bikes during the day ( fix about 20-30 a day on average). I end up getting all the Avid brakes I can fix. Nearly always the same thing, don't use it for 6 months and the caliper pistons freeze up (grateful bike owners pay me with really excellent South African wine). Cheap components break, a lot. I really have never broken a well engineered component on any of my bikes. The XTR on my old Dean has gone 17,000 miles, no failures. SRAM red, 12,000 miles on the Scott Cross bike, no failures. Now I do waste wheels, wear out chains, sprocket idlers, pads, cables and so on.
I am again not a big fan of disk brakes, tiny braking area, even on the largest rotor. Pads overheat, even with the addition of the newer heat sinks along with the spoke windup, drives me mad on hills (this is where the hub will stop rotating and the rim still moves a bit) and I don't run cheap wheels. They squeak like old VW brakes. I still favor the old ceramic coated rims with V brakes. They will launch you over the handlebars and deal with wet really well. The point to this is, marketing has convinced most that disks are better, physics 101 teaches different. Most folks cannot do math. So the big thing is they sell the wheels and older high end components on eBay, for cheap, really cheap. So you can build up a bike for pennies that would have cost 4 figures 10 years ago. It will never break and be super light. Why do manufacturers like disks? They can machine build the wheels really cheaply. No machining on the rims, no humans truing them for the final fit. They give them to the racers to peacock around and the marks buy them. Racers will do anything the manufacturers say and are really honest non- drugged up, would never cheat, riders. Believe anything they say.
Tires are also important. There can be a huge difference in the ride of different tires, not to mention the weight factor on some. Only use gnarley knobbies if you plan to only ride trails. If your folder is for going down dirt roads, get something with less rolling friction, like Town an Country's by Continental or some of the Schwable Cylocross patterns (Rocket Rons $$!). I ride my cross bike with a very subdued Continental pattern at least 10 miles on nasty dirt trails from Flagstaff to Winona and then back on the roads. I can cruise comfortably on cross tires in the +20mph range. If I do the same ride on knobbies, well 16-17 is all I can manage and my lungs are bleeding. It is friction. Buy your tire for 80% of your ride surface and don't cheap out.
Learn a bit of bike repair, it is not hard at all. Plenty of guides on the net. Get good quality components and wheels, especially the wheels. You will end up with a superior bike. Personally I like good shifters and brake handles. Carbon handlebars are cheap as well.
