I am asking because he is threatening to not pay and I need to understand when rent is considered delinquent to issue the "pay or vacate" notice.Please help! 

Be prepared with being comfortable with threatening to be sued and booting people out that day when they pop positive.

They have really low reviews and the reddit threads have a lot of individual experiences.They are rated pretty highly on trust pilot, but when I wrote a negative review on trust pilot, they threatened to remove it.

The public, after all, will decide where to live, where to open and run businesses, and how much to pay for CA property.I happen to agree with Kelly's view that change in perceptions doesn't get "accelerated" until there is an "incident"...Just as the middle-aged man who, after surviving a life-threatening heart attack, finally begins heeding his doctor's advice to eat better and exercise more, Californians won't think twice about changing where they live unless (or until) an "incident" occurs which dramatically impacts their current way of life.

Our repair had not yet taken place when their inspector stopped by - they threatened to cancel the policy if we did not repair the buckling. 

You bait and switch rent cost (you tried to do it to me from 1800 to 2500, but only after I scrubbed your place, patched the holes,  and completed half a full house interior paint- also as a contracted cleaner on your other clean jobs - you got thousands in free work just to scam us)Once we caught in to the scam and said we weren't interested in the new leasing terms you sprung on us after all that work and our own money,  you THREATENED TO HAVE ALL OF OUR BELONGINGS REMOVED FROM THE GARAGE AND CARS TOWED WITHIN 24 HOURS!!! 

The tenant refused to leave, threatened to sue.

I'm unfortunately talking from experience on a rental I was in-- owner was threatened with fines.

@Carly M. i'm not an attorney but regardless of what they did or did not do, I would not recommend "threatening to ruin someone

When you are telling them you are putting yourself ahead of them [maybe unconsciously] and they feel threatened and jealous and they are coming from a place of fear and thus say things disparaging or negative or stupid.If you were telling someone that had 100 units or 1000 units you would craft that message differently and their response would be different, probably more positive.Unless you really need their input, lips quiet, money talks.