i'm shopping for a new 15" MBP. I know I want 2.5 Ghz, 512 gb SSD so without discrete graphics it's $2400 and with its $2500. I don't think I need discrete graphics but a $100 more is not a big difference. I care more about battery life. Is the battery life better with integrated graphics? I know 'officially' it's the same, but realistically? I'm a software developer and I'm into photography so I use Lightroom. I don't play video games on my computer and I don't edit video. Is there any use for me for the AMD graphics?