I would be wary of the HDMI out, until I see that there's a graphics card in this thing we're talking about integrated GMA3150 intel graphics - max digital resolution of 1366x768(according to toms hardware guide for the atom pineview lineup). This IS(possibly, a typo on the 2 pixel difference?) the same resolution as the screen, and therefore I think your viewing experience has a good chance of being better on the Acer than on the Samsung. The Samsun screen is well out of spec for getting a digital signal for the display - 1280x800 is 42 pixels taller than the maximum digital signal the Atom's graphics can handle, and the vga port on theirs indicates they tapped into the analog signal output rather than the digital one.
The Acer went for the digital signal, apparently. We might see that they did it just for the HDMI, but with a digital signal you are much more likely to get a display worthy of it.