One area that is almost always over-looked is the piston rings.
If someone goes to sny. oil to early when using a moly type rings the rings will take forever to seat.
An example would be the JE plasma rings or the Speed Pro Hell fire rings.
I have had a few customers that switched over to early to the syn. oil.
Even after 20 hard dyno pulls at 7,500 rpm's or more a good moly ring like the ones listed above have not fully seated.
In the dirt burner engines I build even after hot laps, the main and the feature you will still see a very small amount of smoke coming out of the breathers.
In a street car with a good moly ring I would not switch over until you had a min. of 3,000 miles on the engine.
When you do switch over don't be surprised if you see the engine use a little more oil also.