I am pretty sure that their 3600 kit is also even tighter. Their previous kit with the tightest timings at 3600 was 14-15-15-35. I personally bought one of those kits and further tuned it to 14-15-14-30 with many of the sub timings substantially lower as well. G Skill makes some great kits.
Technically this is the same Trident kit they have always had, it just sports a new XMP profile that bumps the voltage to 1.55V so it can handle the higher frequency and timings. If you have the Trident Royal kit already, raise the voltage and see what you can do with it, I bet you wont see a difference.
So, what do you get for the extra $$$, a new XMP profile and warranty to run you memory at this high of a voltage! Same chips, same package, same everything else.