Nothing wrong with the new Piglet's, I've been a happy owner for the last 6 months and ride it pretty hard. I run a 120mm reba on the front so can't comment on how it would behave with 140's.
It's well built - you're not going to have any problems with the frame breaking. The early ones that had cracks develop had the seat tube incorrectly reamed but they were isolated to a certain batch. No problems since as far as I know.
As for whether you want a Pig or a Piglet I've never ridden a Pig but I'm guessing it won't climb quite as well and will build up a little heavier.
If you need any specific info just let me know.