I've been doing some same day turns - DCA-IAH-LAX and back same day. The schedule is such that I come back on the same aircraft at 12:35pm from LAX. Get the same flight crew - they do a turn. Coming back on the same aircraft insures you will make the return back to IAH. I have a SFO turn this weekend.

I do not need the EQM - just the miles.

But I think it makes more sense to spend one night at the destination - the turns make for a very long day. You might be able to head over to South Coast Plaza for dinner, etc. for something to do.