After reading load distribution alternatives and giving my limited skills on the area I'm biased toward round-robin DNS strategy.

From what I understood, one key aspect of DNS Round-Robin is setting a low TTL value, avoiding caching.

My main concern is that all my traffic comes from mobile networks, almost 30% of that comes from t-mobile 3G. Some questions:

1) Is there a chance that almost all clients on the same mobile network will be redirected to the same IP in the TTL frame? That would kill the distribution technique.

2) If I choose a really low TTL (zero or one). That impacts directly over client performance? It does a DNS miss every time or it's a setting that only impacts on DNS servers?

Any help would be much appreciated. Thanks