Well, there's the crux. Corsair claims the H50 has ultra-low-evaporation tubing. Judging by the stiffness, there is probably something to that claim. However, they've only been on the market a relatively short time. We don't know the evaporation rate. There isn't much fluid in those things. Even at a very slow rate, how long will it last? We just don't know. That you cannot refill it is definitely something to keep in mind, but only in the very back. It'll last through the warranty period (two years), or that would be shorter. Most people replace their cooling solution more often than that anyway, but FWIW.