I have seen this advertised on a number of folding bikes including, Downtube and Birdy. After a little reading including the Sheldon Brown article I can see why it makes sense on a bike with smaller than standard wheels.
I have two questions for all or any of you.
1) How would you compare this in quality to other Shimano groups? Equal in quality to Ultegra or Dura Ace or not up to that level?
2) Since I have been thinking of buying a bike where this is one of the options what do you think? Would you choose a bike with this component group?