Yes it's a watercooler. Looks like a Corsair H50 with a different top (are there OEM/rebranded versions?) Personally, I wouldn't bother swapping a Fenrir for a H50.
Not worth it. The Corsair H50 is a much upgraded version of the LCLCs used in Alienwares, HP Blackbirds etc. The Corsair one is the only one worth using. Be aware that these are Corsair numbers, but they're still fairly accurate based on the reviews I've seen of the earlier LCLCs.