My two centavos:
I went to Sportsmobile to look around. Was extremely impressed on how they were doing work. Nothing was "piecemeal" about what they were doing, be it how the PowerTech generator was mounted under a Sprinter, with the angle of departure known and engineered to minimize chances of it encountering obstacles (the genset was mounted above the axle, and the hitch had a skid wheel, so it an obstacle was significant, the rear hitch would take it, not the generator's enclosure.)
Each hole, when cut, was promptly painted with a primer and followed up with some type of paint around the aperture, so that water intrusion via that hole was kept at bay. Even things like the line between the external fuel fill and the FW tank could be drained so one could be in sub-freezing temperatures, but still have access to water and electricity.
Running high quality can be done. Businesses have had decades to figure out how to get workers to do something, inspect it, correct issues, then repeat until the product is ready to hand over to the customer. Yes, the employee using a screwdriver to punch holes might be faster, but long term, that will cost the company more cash over time due to warranty issues. There needs to be quality inspections and active corrections if a fault is found, and an employee doing the job right with a hole saw shouldn't be punished for doing the job right. The time difference may be less than sixty seconds between punching a hole, versus using the hole saw... but the quality difference will be there for the life of the rig.
As for foreign competition, it is unlikely to happen... the RV market is just too small. Hymer is poking at the US, but they have years to go before they have more than just Roadtrek branded vans in the US market.
Time will tell. If the bottom doesn't fall out of the economy, European companies like Hymer may actually get a solid base of customers because of that style of rig.