Well, unless the guy is a scamster then that scan converter should work just fine.
The reason you don't see anyone using a converter like this is because unless they are very expensive the picture quality is normaly, well, trousers, quite frankly.
So yes, it will work, but probably not a whole lot better than any other scan converter that you got from frys or radio shack or whatever.
If you want GOOD image quality you really need a proper arcade monitor with an arcadeVGA/Jpac. if your budget won't stretch to that then a SCART TV with a hacked cable to get the RGB signals from your video card is the next best option, failing that Svideo out will be ok ish and composite out will be worst of the lot.
THe main advantage that thing has is htat it's a peice of consumer electronics, you can plug and go. If you decide later that you want better quality then you can look at your options.