I vote plug as well.

If you lose oil pressure your engine is shot.

Unless you have a super cool aftermarket gauge that lets you know when you drop below 20, it wont help you.

Even then, 20 psi at wot for example wouldnt be enough.

Only time i see the point is if road racing, however oil temp would also be a concern.

Even then, how often do you glance at your gauges?