It's not bad. I am currently using it on three cars. I plan to remove it from one car, and switch back to Zaino, because that particular car is dark blue. Einszett cannot be layered and since dark blue is susceptible to swirls and scratches, I prefer to use a layerable wax on the dark car. I have no emperical evidence which suggests that Zaino will provide more protection than Einszett, but my gut instinct is that because Zaino is layerable, it will give me an extra measure of armor, so to speak.
I must say that Einszett is one of the best looking products that I have ever used. It is much deeper than Zaino, and is just about as reflective. It also seems quite durable. However, it is not as deep as a good carnuba. It looks especially good on my wife's silver Mercedes. While silver cars don't ordinarly benefit that much from depth- I have used Blitz on the Mercedes, and it didn't do much for the finish- Einszett looks fantastic on it. The depth really helps the shine; I will be sticking with Einszett on this car for sure.
I also used it on my father-in-law's beater, a 1991 Taurus. This car is never garaged and spends a good deal of time parked under a palm tree. It's been three months now, and Einszett still looks great and beads nicely.
BTW, I also have the Einszett polishes, and they are really outstanding products. They are much better than the 3M polishes, IMO- Einszett breaks down much faster. The trade-off is that Einszett is less agressive, but that doesn't bother me. I'd rather use a polish that is too mild than one that is too harsh. Also, if the polish that I am using does not get the job done, I can always use a more agressive one.