c# coroutines

Using the DimeRocker API in c# requires a lot of coroutines. I'm starting to get the hang of them and I feel the Post Score example could be improved. It says:

StartCoroutine( drClient.leaderboard.PostScore( leaderboardId, localUser.GetId(), newScore, new ArrayList(), 0, 0 ) );
// Wait for PostScore to complete before fetching the record
yield return new WaitForSeconds(2);

Now just waiting 2 seconds is unreliable. Isn't it far easier and more reliable to use:

yield return StartCoroutine( drClient.leaderboard.PostScore( leaderboardId, localUser.GetId(), newScore, new ArrayList(), 0, 0 ) );