I found this thread looking for a rack. Bought one from Walmart and used it to commute on Amtrak for about a year. Still riding it around town from time to time. I haven't yet read through all of this thread (appreciate the great info so far!), but here are some of my experiences:

Bad:
- Out of the box the headset was too tight and notchy (local bike shop tuneup fixed it)
- Right pedal came loose and started to tear up some of the crank threads. Caught it early enough to retighten and all is well so far.
- Cassette came loose and bearings grenaded. $25 to replace at local bike shop.
- Brake lever set screws backed out (one lost, the other loctited back in place).
- Creaking from somewhere related to front folding post (I think... haven't spent any time yet to investigate).
- No water bottle mounts.

Good:
- Inexpensive.
- Folds up nice and compact. Fits nicely in car trunk, worked great on train.
- Has top & bottom rear rack mounts.
- Shifter & brakes work great.
- Welds look clean and solid.
- Rides great (currently I'm a flatlander... you hillbillies are on your own

Recommend:
- This is the first non-local-bike-shop bike I have bought and learned some hard lessons. If you buy one give it a through once over or take it to a bike shop and have them clean up the assembly to save yourself above issues.