I used plus nuts over rivnuts for the following reasons:
1) hole does not have to be very precise.
Precise holes are still better and not more difficult
2) No. 1 allows use of a step drill.
Step drills are fine but why not use the correct drill to begin with?
3) No. 2 reduces chance of drilling too far
Everyone should have a set of drill stops they aren't expensive.
4) greater pullout strength
Probably the best reason in many cases but in a van conversion not really important.
5) no special tools needed (I used battery impact driver, wrench, #8
bolt, washer, connector nut, star washer)
6) repeatable install (10 turns for me, made easy by black marker line on socket, I first tested to determine this spec)
Astro tool - one good squeeze.
7) can be put in pretty tight places
8) less likely to spin imo
Always buy the Rivnuts with the splines to prevent spinning.
9) if they do spin, a small hole allows you to block the spin with a nail stuck thru it
They are a little harder to source and over a $1 a piece at low quantities.