I bought a Paratrooper to use while I was away, as I traveled a LOT (truck driver, and for a while, trucking safety instructor). I'm a big guy, and the frame has held up extremely well during the last few years.
I found the crankset to be a cheap unit, with riveted 'rings, and I went ahead and replaced it and the bottom bracket at the same time. A Hussefelt downhill set I picked up at a discount work very well.
The seatpost was a bit short for my 6'4" height, so I picked up a longer Bontrager in a San Antonio bike shop. Once the seat was at the proper level, I found the handlebar height uncomfortable (ah, but a few years ago...), so I installed a stem riser.
The bike isn't as lively as the Cannondale I sold to make room for it, but it fits in the trunk of a car, in the back of the Cessna, and is rock solid when set up to ride. Adding a solid rack interferes with the folding function, so I picked up a QR rack, and while I had a small front rack mounted on the brake bosses (the bosses aren't used with the disc-equipped models) I removed it due to its rubbing the rear wheel's spokes when folded. It's still visible in this pic, though, and will likely be re-mounted if I decide to tour with this bike.