At 21.5 inches across, the ViewSonic VSD220 Smart Display is the size of a standard computer monitor. Aside from the multi-touch optical touchscreen tech that's built into the bezel, its display looks a good deal like that of the computer monitor too.
It uses a 1080p panel of the TN type, still the most common sort found in low-cost screens. The benefit of TN screens is that their response times are quick, eliminating motion blur issues. They're not so hot on most other fronts, though.
The ViewSonic VSD220 Smart Display's picture quality is unremarkable. Colours aren't particularly lively, areas of black have a slight blue-ish tint to them and if you view the screen from underneath, contrast shift robs the image of any presence. Of course, this is not a screen that you're meant to look at from below, and horizontal angled viewing only causes some loss of brightness.
This sort of performance is standard for a screen of this type, but it's not the only kind of touchscreen you can get at the price. The Dell ST2220T uses an IPS panel and similar optical touch technology, but doesn't have any Android goodies - it's a dumb monitor.
Here's the issue - there's not much out there like the ViewSonic VSD220 Smart Display. This makes it on one hand an interesting device, but it also makes quantifying its worth tricky. If you just want a touchscreen monitor to use with a Windows 8 computer, you can get non-smart alternatives for around £100 less. And if Android is the main draw, it feels better within a tablet.
Do you want both a touchscreen monitor and an Android box for the house? The ViewSonic VSD220 Smart Display is a surprisingly good entry, given the quality of some of ViewSonic's past Android tablet efforts, and even if you don't like the feel of using such a large touchscreen, mouse input is only a minute away.
The ViewSonic VSD220 Smart Display arrives at an opportune time. It's a smart monitor that can be used on its own as an affordable Android-based all-in-one PC, or with a computer as a Windows 8 interface. Thanks to its decent multi-touch optical screen, it can handle basic Android tasks well too. However, as the display quality isn't that hot and Android can be hard work on such a large screen, it's not quite the perfect solution.