My main reason for buying the Logitech G1 mouse was the fact that it had an attractive price, combined with the enhanced resolution engine (800dpi). The retail price of €29 can be considered as low entry, when high end solutions cost around €60.
In the short time that I have been using the Logitech G1, I found that it has very good response, especially compared to the previous Microsoft Basic Optical mouse that I was using. In fact, the reason I opted to try a different mouse was in an attempt to find one with sharper response and in that sense, I can say that it was a successful buy.
Lastly, the G1 mouse is covered by a 3 year warranty, whereas other Logitech mice are covered by 5. We don't know why this mouse has a smaller warranty period. Hopefully, nothing will happen to it during those 3 years. More likely though, I will have been enticed into purchasing a newer, better mouse by then:-)