Until I'm shown a laptop with better specs (within your price range), I'd say go for the Acer laptop. What's most important to you is the GPU, and the HD 6850M is the best one so far for your needs.
EDIT: In response to the "squeamish about Acer" comment, my dad has an Acer laptop and we've never had any problems. Even with others, the broken Acer laptops I've come across can all be attributed to misuse (spills and overheating). I've never actually encountered an Acer laptop with a design flaw (unlike HP).