Adding a Mileage Run To Regular Flight?

Hi,

I'm booking travel in December and I noticed that United seem to be making things easy for us by building in Mileage runs!

For example, I need to fly SMF->LAX. I could fly there direct for 500 miles, but
there are loads of other options with the exact same price.

1) SMF->SFO->LAX (1000 miles)
and even
2) SMF->DEN->LAX (1500 miles)

All arrive at LAX around the same time, but leave a few hours earlier.

So which is the most dependable of 1) and 2). I need to be at a meeting at LAX so don't want to be late.