Nope, not my opinion. All independent testing on synthetics versus non-synthetics in non-high performance engines, operated in moderate climates has shown the same thing.
If you have a high-performance engine, or operate the vehicle in extremely cold temperatures, then synthetic is advisable.
Advantages of Synthetic
----------------------- Synthetic oil was originally developed for high performance racing engines. Mobil tried to popularize synthetic oil for passenger vehicles back in the early 1970's. At the time, Mobil was promoting 20K or 25K oil changes with synthetic, but they soon backed down from this. Synthetic oil is a good choice if you have a vehicle with a high performance engine (in fact synthetic is required for many of these engines). It is also a good choice if your vehicle is operated in extremely cold climates. It has higher resistance to breakdown caused by heat and it flows better in extreme cold. Unfortunately for the synthetic oil industry there is virtually no advantage to using synthetic oil in a non-high performance engine that is operated in moderate climates. Synthetic may give you the peace of mind of knowing that you are using an oil that is better (in theory) than necessary for your vehicle, but it won't reduce wear or extend the life of the engine.
The mistake some people make it to wrongly extrapolate the benefits of synthetic oil from high performance engines (or engines operated in very cold climates) onto normal engines operated in mild climates, with the ultimate lack of any knowledge being manifested with statements such as "synthetics provide 'Peace of Mind,' or 'Cheap Insurance,'" or other such nonsense.
Extended Change Intervals
------------------------- Most manufacturers of synthetic oil advise users to not exceed the manufacturer's recommended oil change interval. Part of this is self interest (they don't want to be liable for any damage) but the real reason is that synthetic oil, while it does have certain advantages, still becomes contaminated.
Be extremely wary of synthetic oil companies that offer to pay for your repairs if it is determined that their oil and their extended change interval recommendation caused the problem. Think for a moment of the incredible hassle you would have to go through to prove responsibility for an engine problem. Who would pay your legal bills? Who would pay for replacement transportation during the battle? The more bizarre the warranty the poorer the product is a good rule of thumb.
API Certification, Phosphorus & ZDDP
------------------------------------ Never use a non-API certified synthetic oil (there are many of these on the market). The problem with the non-API certified synthetics is that they contain too much phosphorus (in the form of the additive ZDDP (Zinc Dialkyl Dithiophosphates)). The API has limited the amount of phosphorus because phosphorus shortens the life of the catalytic converter. These oils are fine for snowmobiles, motorcycles, and older cars that don't have a catalytic converter, and the extra ZDDP does provide additional wear protection.
Unfortunately, some marketers of some the non-certified oils do not explicitly and honestly state the reason for the lack of API certification. You can check the status of API certification on the API web site. Be certain to go not just by the manufacturer name but by the actual product as well. This is because a manufacturer will sometimes have both certified and non-certified products. Suffice it to say that Mobil 1, Royal Purple, Castrol, & Havoline all make synthetic oils that are API certified and that can be purchased at auto parts stores and other retail outlets. Amsoil has one product line, XL-7500 that is API certified, but it's other lines contain too much ZDDP to be certified and should not be used in vehicles with catalytic converters.
Amsoil
------ Amsoil actually makes some good products. The negative image of Amsoil is due to their distribution method (MLM) and their marketing approach. If Amsoil products were competitively priced with Mobil 1 and other synthetics, and if you could buy them in a store, their XL-7500 synthetic would be a legitimate alternative to Mobil 1.
Amsoil didn't disclose until recently (and then it was by accident) the real reason that their oils (except for XL-7500) are not API certified. In the past they came up with all sorts of bizarre excuses about the reason for their lack of API certification and this greatly contributed to the distrust that people have of the company.