Super seeding to limit share ratio?

[NLZ]

Seeding limits gives the option to either pause/delete or set the torrent to super seeding when the limit is reached.

I know that theorically super seeding is supposed to help even out the initial swarm, but in practice is it an effective seeding throttle on long term seeding, when there are a lot of seeds and only a few leeches? Or why else is it an option in seeding limits instead of just setting an upload rate limit?