One area where you would expect the VPC100 to excel given ViewSonic's pedigree is its screen and though by no means class-leading it does actually perform better than some monitors we've had through the labs. It's a bit low on dark detailing but colours are bright and engaging, text is sharp and viewing angles are reasonable. Only the screen's resolution is a cause for disappointment, which at 1,366 x 768 is lower than we had hoped, but largely sufficient for most needs.
For integrated efforts and considering their measly 3W rating, the stereo speakers aren't too bad either. Though they have a very low maximum volume there's no distortion, trebles are fairly clear and there's even a modicum of bass; certainly adequate for everyday activities and YouTube, though listening to music and films is better done using headphones or external speakers.
Whether the VPC100 is good value is anything but straightforward. At £375 it's far cheaper than other Atom-based AIOs we've reviewed, but lacks a touch-screen. Its strongest competitor is thus Acer's Aspire Revo, which can be bought with the aforementioned VX1962wm 19in monitor for around £360 - giving you a better, higher resolution screen and far more powerful PC (thanks to nVidia's ION chipset allowing playback of Full HD material and even some 3D games) with more memory and connectivity for less money. The only thing this package is lacking is an optical drive, though an external USB unit is only around £30. Of course part of the appeal of the VPC100 is that it's a real AIO, but with the tiny Revo monitor-mountable it's not necessarily that big a difference.
If you must have a true AIO and don't care about touch-screen, the ViewSonic VPC100 is definitely worth considering as it's one of the cheapest machines of its type available. Competitors from the likes of Lenovo, Avaratec and MSI might be slightly better specified, but demand considerable premiums.
A fairly attractive and well-built machine, ViewSonic's VPC100 19in All-In-One PC is slightly let down by its terrible keyboard, limited connectivity and weak internals, but makes up for it by being very affordable. However, if you don't insist on a super-slim all-in-one, it's worth looking at the alternatives first.