Quote from the review at BIOS Magazine:
"Acer's Aspire 2020 series is the company's first laptop to include a widescreen design. The system's simplistic design and multimedia features will also appeal to those looking for a relatively powerful and mobile desktop replacement system. There's no built-in Bluetooth as standard, no digital video output, and the 15.4in. screen has a native resolution of just 1280x800 pixels, but it offers an attractive combination of good looks and mobility for general users. High-end graphics users will want ATI's new graphics chipset and a higher resolution screen, and business users will find the multimedia controls on the front of the system a little annoying, but the Aspire 2023WLMi is still worth a closer look."
The above would put me off the Acer; but having said that, I am no great fan of Sony either! Teh spec of the sony machine at Dabs click here seems good for the price.
Why have you narrowed down to these two? I should have thought that there are better options out there for your money?