Bear in mind, my ex was a 1999 Birdy silver, Sachs 3x7 (21 speed)

Likes:
- Beautiful design
- Plush suspension works well
- Folds well (but nothing to hold it together, i.e. kind of floppy)
- Fairly light for the package (compared to Bike Friday, Dahon, or Brompton)

Dislikes:
- First folding bike - found out I'm not a fan of aluminum
- Springs are creaky - made a lot of noise esp. when cranking hard
- Paucity of 18" rims, tires, and tubes
- Hinge was prone to getting loose - suggestion was to bang the rod back in, and use locktight around screws so it wouldn't come out
- Brake pads would wear into the rims
- Sizing didn't fit that well for me (now I hear the sizing adjustments are a lot better)
- Hard to get accessories (rear rack, fenders, elastomer, etc.)
- Pedal and gears had to be in a certain position before folding, otherwise the chain derailed easily (however, this was not a huge problem).
- That big sticker which reads "BIRDY".

The new monocoques look nice, but they don't seem to be in the U.S. They also seem to be a favorite of the BionX system. If you know anyone in the San Francisco Bay Area, someone on craigslist is trying to sell a Birdy Green (now Birdy red) for $400.