Synthetic Oil - good or bad?

I agree, regular and frequent oil changes makes a huge difference.

As for conventional oils....I have to admit I'm surprised the oil companies have continued to produce it, and continued to improve it. Every year, the demand for it must be decreasing. But the modern conventional oil is a very good product with lots of R&D behind it.

I put little faith in anything a dealer of any product tells me. They have no actual operating experience, and their motives are never pure.