While it's not the same exact model, I have a ViewSonic A90 as my primary monitor, and I've been fairly pleased with it over the past year or two. However, there are a few minor annoyances with my particular monitor:
- The power switch is flaky (sometimes doesn't work). I now turn my monitor and speakers on and off with a power strip, so this isn't much of a problem any more.
- On rare occasions, the monitor will get caught in a weird mode coming out of it's "power save" state. The monitor makes a loud clicking noise and fails to display. I have to toggle the power to it to fix the issue, which causes me to run into the first problem above.
- At high resolutions (1600x1280), I can only run at 60Hz, which causes noticeable flicker. 1280x1024 runs just fine.
Other than these few items, I've been pleased with the performance. Since you will be using it as your backup monitor, I suggest you go with ViewSonic. You get pretty decent reliablility for a great price.