Having one of my own, I now know that the typical off-the-shelf Birdy is in the same sort of weight ballpark as any other folder. There are people who have lightened theirs to a scrawny 8kg! That would be difficult though. 10kg ought to be straight forward.

As for folding speed, it's much like other folders as well: once you know exactly what to do, you can get it down to 15s with no trouble.