The concept of tablet-as-desktop (or, tabletop PCs) has been growing a bit since Windows 8, and it's an enticing proposition if the price and design are right. The new Sony Vaio Tap 21 seems to hit on both fronts, offering up a very attractive, very portable touch-screen 21-inch PC. Hopefully it'll prove to be affordable, too.

The Vaio Tap 20 came out last year and was one of our early favorites in the tabletop PC world. The landscape's expanded since then, but the Tap 21 has an aluminum chassis and easy-fold rear stand/hinge that give the PC all the appeal of a well-build monitor/tablet with a bit of the feel of a TV. It's also 30 percent lighter than last year's model at about 8 pounds, despite gaining in inch in overall screen size. It might be the first big-screen tabletop PC I've felt a longing toward: its crisp, solid design already feels like a winner. We got to see one up close, and its design improvements seem like a big step forward from the more plastic Tap 20 before it.

A clean rear kickstand that feels lightly spring-loaded. Dan Ackerman/CNET

Like many other tabletop PCs, the Tap 21 has a built-in battery for a few hours of runtime before plugging into an outlet, which you can view as "tablet mode" or battery backup in case of a power outage, your pick. Most people will probably see the Tap 21 as a highly portable 8-pound PC rather than a true big-screen tablet: that rear stand doesn't fold down completely on its own, springing slowly back into place after being bent back. The Tap 21 can be outfitted with a Core i5 or 7 processor and either solid-state or hybrid hard drive storage, and comes with a fair amount of included software: Sony's Fingertapps touch organizer, a family calendar app, and a Sony Imagination Studio Vaio Edition software package (Movie Studio Platinum, Acid Music Studio, and Sound Forge Audio Studio).

Tabletop mode: ah, the possibilities. Dan Ackerman/CNET

The Tap 21 is far from the only tabletop PC out there; in fact, you can find a lot of options. But the Tap 21 could end up being one of the best.