Can't say I agree with the above, and I typically steer clear of these types of discussions since they're extremely subjective with multiple factors affecting longevity. I think Tourna Big Hitter is a great string, but there's no way it last longer than SPPP and Silverstring. Cyclone - I wouldn't argue that. If nothing else it's close, but certainly not the first two.
I think if you like SPPP and SS, you're pretty much maxed out as far as longevity is concerned. If you're paying for restrings, consider a stringer, then you can play with any string you want and not worry about longevity.
Need help finding lost dog: walks with a limp, recently castrated, can only see out of one eye - answers to the name, "Lucky".