Well KWA has a longer warrenty. I have heard (not sure if this is true or not, this is just what my local retailer said) that G&G customer service sucks.
G&G might be a good choice if you want to upgrade later being that KWA rocks out of box. I'd go with KWA. But if i were you i'd really go with CA, although i have heard that G&G is on par with CA now. But that's just IMO.
Good luck.
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