There's nothing wrong with leasing transport. Almost all of NTT's network is leased, and pretty much everyone agrees they're a top flight network.

The thing that makes HE unique is that they only sell full ports. They don't do fractional billing or 95/5. You pay for 10gigs on that 10gig circuit, regardless of use. This leads to networks running HE ports near max load at peak time. From HE perspective, this is great because it's super easy to plan for and scale out. You're never surprised by a customer who goes from 3 gigs to 92 gigs on that 100gig circuit.