The main case that I know of where you really don't want to use open addressing (using tombstones) is when you have both of the following requirements: a) need to repeatedly insert and delete items, and b) can't tolerate (relatively) really bad worst case insertion performance.

I can't speak directly to the performance of non-tombstone based open addressing implementations, but it definitely seems like the need to move things around after deletions would be significantly more work than the fastest chaining implementation I've come up with.