Tuilagi is an impressive runner, but he doesn't really have the rugby smarts of the other too - or indeed Jonathan Davies. Have a feeling that might get him found out at the highest level in future, unless he improves.
Roberts will start, because he's the only full- time inside centre on the tour, BOD an obvious shoo-in outside, and Tuilagi will probably be on the bench.
Waratahs game's another that won't tell us much, sadly. Personally, think the weakening of the pre-Test teams is in some way deliberate.