TIMER: I am not an employee or a dealer for SynLube. I am a customer only. If you wanted to buy SynLube from me, I would refer you to the company.
As far as having used another good synthetic, why? SynLube is better than any other lubricant in my opinion. SynLube lasts 150K miles/3K engine hours/10 years, WCF. At that time, I'll send it back to SynLube who will microfilter the lube and rebalance the additive package. It will then be in brand new condition. I even get a credit from the company if I exchange it for new SynLube. During this time, I will not be producing hundreds of quarts of waste oil which is a growning disposal problem in this country and is considered a toxic waste.
As far as economy goes, you pay up front for SynLube. I am anticipating that I'll only have to spend $195 for the 150K mile period. Plug in your figures for what you use now. Even if you change your own oil, you should still come out ahead but the savings are not my main motiviation. It is the performance of the lube and the knowledge that it maintains its like-new capabilities over its entire service life. The service life for the lubricant given by the company is actually quite conservative according to their website.