I guess that depends on your understanding of "vesting" - and my understanding may be faulty.

As I understand it, if I leave the business before the vesting I get nothing. When the stock vests it becomes mine.

A lock down of the stock then means I can't trade it, but it remains mine (regardless of whether I stay or leave.) Once the lock is lifted I could sell it.

So in that sense there's a difference, yes.