Between the two, the Toshiba would be my choice too. Toshiba Portege R835-P56X Review
The Acer has longer battery life which explains a lot of it's 1lb heavier weight.
The NVIDIA GeForce GT 540M graphics card of the AS3830TG is more useful for gaming than for watching videos.
The glossy/glare-prone screen of both models is drawback for a commuter.
If you were starting all over again, I'd suggest the Dell Vostro 3350Dell Vostro 3350 Subnotebook review
A pound heavier when equipped with the big 8 cell battery that you'd want to choose. (or keep a spare 4 cell battery at the office).
Performance of all three mentioned here would be very close and exceed the performance requirements for the tasks you mentioned.