New iMac and Gaming

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For the past several years, I've used a late 2009 iMac for gaming, but its getting long in the tooth. How well will the newest round of iMac's do for gaming (in Bootcamp), do you think?

Specs I am planning on getting:
27" Screen
3.2Ghz Quad core i5
16 GB Ram
1TB Fusion Drive
Geforce 680MX (2GB GDDR5)