As an owner of a fractal design define R4 the H440 is definitely not a rip off of it - the only major similarity the two have is that they both have case doors on the front. Other than that they're very different cases altogether. Any similarity besides that is most likely because they are in the same price range thus will have similar features.
As for this rebrand I guess if you $80 extra on top of $120 for the initial price of a vanilla H440 its a decent buy. Especially if you're a fan of razer or just want an all green and black color scheme.
Personally I'm not a big fan of LEDs but razer's green on matte black scheme is okay. Really it'd just be cheaper to use cathodes or do some crafty case modding to get a similar effect without the razer logo in the mix.