First off you'll notice the haze in the clone (one the left). I'm not 100% sure why there is a haze and I'm not really worried by it. Second is the head on the clone. Its big and its lasts, all the way through. On the Epic, it doesn't.
Next is the aroma. This is where the NZ Cascade comes into its own. Biggest thing I noticed was more passion and tropical fruits from the US Cascade. NZ Cascade was more citrus and was much more dominant. Taste is very much the same. Epic have done an amazing job with their Pale Ale and I still rate it as one of my favourite beers, but, I think if they were to use NZ Cascade, it'd be MUCH better.
I guess it comes down to why you brew. I brew because I enjoy beer. I brew because I enjoy brewing. I brew for myself and SWMBO, but mainly for me. I enjoyed it and I will brew it again and again. House Ale I feel.