Don't despair; new tool rollouts are always a hard sell -- especially when replacing a beloved classic.

For me, the killer feature would be "ease of use."

Sure, I _can_ make rsync do any number of rarely-used optimizations, if I feel like studying the manpage for half an hour and figuring out how to fit it to my exact use case.

If your tool has the same features but is automatically adaptive -- I'd use it.

Copying thousands of tiny files in deeply nested subdirs? Just works. Copying a huge file that's already encrypted? Just works. Copying a mix? Just works.

No special flags to set, zero config. It just works, optimally, every time.

"Reducing the user's cognitive load" is the killer feature here.