The Nintendo DS was a pretty big hit among portable gaming console fans, in part because the two screens were pretty neat and afforded a higher level of video game complexity. According to early reviews of the Sony Tablet P, that might not work as well on a tablet. Walt Mossberg says Sony’s entry into the Defeat The iPad Wars doesn’t quite measure up. Mossberg praises the P’s predecessor, the Sony Tablet S, as being a fun tablet made to look and feel like a magazine page, but the P has problems:

The most important one is that, to take advantage of its full viewing area by using both screens as a single display, you must put up with a thick, black, plastic bar across the center of whatever you’re viewing. That disruptive scar is the inside of the hinge, where the dual screens meet.

Some apps avoid that absurd situation by cramming all their content into just one screen. But these screens are small, just 5.5 inches diagonally, closer to the area of a large smartphone than Sony’s Tablet S or the iPad, whose screens are about 10 inches. When content is spread across both screens, as it is in the Web browser, the combined display is about 7 inches, but that black bar is present.