1. You can get a long line in your T/R ..... in fact a friend of mine killed himself in New Guinea when he got a line up in his Hughes 500 T/R.
2. Both the Bell 212 and the 412 also have a sling Vne of 80 kts.
Reason ....don't know ...could be that they have only flown the A/C up to that speed to prove safety and controllability ... saves money not having to fly more ... so they make that the (somewhat artificial) speed limit!
Cheers
