Your Luthier friend is a smart person! I love oil finishes on my necks. It truly does depend on where you live and what kind of weather changes your guitar will be subject to. I highly recommend a hard finish on our necks as they will last the test of time this way. If you are a touring musician and in changing climates quite often I would stay away from oil. If you do a real fat 1/4sawn neck chances are you would be just fine. Tommy.