The payoff came through escrow exactly as the paper said it would
The part that worried me was getting paid, not the rate. Small three bedroom flip in a working class suburb, all in at 218k purchase plus rehab, hard money senior funded 175k, borrower had about 21k of his own in and needed the rest to close. I put in 22k at 12% interest only, 2 points, six month term, second position.
Before I funded I did two things I would do again. First, I asked for the senior's note and loan agreement and read the part about additional financing, then got the senior's written consent to my junior lien on the same page as their signature. Second, I recorded my lien (my state uses a deed of trust, the instrument name and the recording steps are different state to state, so check yours) and asked the closing agent handling the eventual sale to list me on the closing instructions as a payee with a written payoff figure.
It closed at month five. I collected 440 in points at funding and 1,100 of interest at payoff, so 1,540 on 22k in five months.
The part that nearly broke it: at month three the buyer's appraisal came in 12k under contract price and the borrower cut the price to hold the deal together. After commissions and the senior's payoff there was roughly 6k left to the borrower. Another 15k off the price and I would have been the person on the phone negotiating a haircut on my own principal, because the senior gets every dollar of theirs before I see one.
What I keep: written senior consent, my own payoff statement into escrow, and reading the senior's documents before I care about the rate.