Specifically Allergan warranties, the new capsular contracture warranty. What do I need to know before making a decision?

I understand there are 2 tiers of coverage and I plan to purchase the 2nd tier coverage. My question is, the new capsular contracture coverage that began in Nov 2014 is that only for silicone? I am still trying to decide between silicone & saline (paid for silicone but I like the peace of mind saline provides/no MRI's). Why are saline a 10 yr warranty & silicone lifetime? Is it really a lifetime or is there 'fine print' somewhere? Any pearls of wisdom provided is greatly appreciated!