As both a sub, and a human being who has been in love before.
I think I can safely say, that what two people consider love, or true DOM/sub relationships, not all will consider the same.
Dependent on how far the relationship is into the activity, some D's can ask their s's to do just about anything, which the s will do. But in other relationships, it may be more for an asthetic value, and control is only limitied to the point of "vanilla" sex.
That doesn't make it any less true love. Just a different kind.
As for the perfect sub part.
Many Dominants do love fully obediant submissives. However, some might cherish a almost completely obediant submissive that they get the chance to "correct" on occassion.
Perfection comes from the view of the individual, not a large group.