I've never tried one of this type stylus before so I'm a bit bemused as to how to determine it's viability. The price is competitive. I tried it on a Kindle Fire and a Droid X. It worked fine on both. It is definitely more precise than my finger on the Droid. The Fire is just as precise but due to the larger size, my fingers aren't quite so clumsy. With the minimal experience I have had with styluses in general, this seems just fine.
If reviewing a product, it may have been received free of charge. That will NEVER have a bearing on my recommendations.