A friend stopped by last year and I worked on his Honda Civic while we hung out. Just for fun I put the Wolfgang sealant on the driver side and the Jescar sealant on the passenger side. Approximately six months later he came over again and both sides were still doing decently but definitely needed a pick-me-up. The car is outside every day and is parked on the highest floor of a parking garage so it gets a lot of exposure to the elements.
Both products performed well, even through neglect, and would have absolutely lasted longer than six months if the car was cared for properly. I echo what other folks say - both products achieve a wonderful result. I lean toward the Wolfgang offering because of its smell and, if applied super thin, it is very easy to remove.