I can't help with the duration part given I change cars to often but I can say I have always used Suntek Ultra and it looks fabulous but in short order I see tears and perforations. So, my point clarity is important but so is the toughness/longevity of the barrier.
What I was told by the Xpel installer, it depends on whether you park your car outside or not as to how long it lasts. He said around 5 or 6 years. I'm pretty sure the warranty is for 5 years. You can use wax or ceramic coating. I wax mine because I like to.