The Toshiba Satellite S855-S5380 isn't really that stellar of an option.
First, the biggest issue with it is that it comes with a 15.6" 1366x768 display. 366x768 resolution in a 15.6 inch display make things onscreen large, and 15.6 inch displays that have 1366x768 resolution tend to be low-grade LCD panels with very poor image quality due to low contrast. You should make a point to avoid displays like this when it is reasonable to do so, unless you require the larger text for eyesight related reasons.
Second, you can do better than the Radeon 7680M, at the same time as getting a decent display, within your budget.
The following configuration of the HP DV6t-7000 comes with a substantially better GPU and display, for $722.
HP DV6t (NVIDIA GT 650M, 15.6" 1920x1080 display) - $722 + tax
- Saved Configuration: http://www.shopping.hp.com/webapp/shopping/load_configu...
- Apply coupon code NB6893
- Don't downgrade the GPU to the GT 630M or to Intel HD 4000 graphics. The GT 650M is considerably faster than either, and if one of the lower GPU options would work just as well for you then I would probably suggest getting an entirely different laptop.
- Don't downgrade the display to 1366x768. The 1366x768 display makes things onscreen large, and is a low-grade LCD panel with very poor image quality due to low contrast. The availability of the upgraded 1920x1080 display is part of why I'm recommending this laptop; I wouldn't be recommending this laptop if it didn't offer it.