On the e545, it's worth another $20 to get an A8 cpu (4 cpus, not just 2, and more shaders in the integrated graphics) and also a second stick of RAM (4GB + 4GB) for improved performance, otherwise I think the RAM will only be accessed in 64-bit mode vs. 128-bit mode. Also, the great thing about this laptop is the highre capacity 72wh battery exists, I would definitely spring the extra $10 for the better battery.