Porcorosso,
I have been flying LOP since about 1997 when the GAMIjectors came out, I believe I had the first set in Europe (sn 1023).
In combination with a JPI -cylinder engine analyser, and a good understanding of the combustion event, you will never fly ROP again unless needed for high altitude performance.
They just passed sn 10000 about a month ago.
They were Aviation Consumer's gear of the year about 97-98.
It is a pity so many pilots and mechanics believe the Old Wives Tales about flying too lean. Please read the rest of John Deakin's engine management columns as well, they are very well done and based on data, not rumours.