Configuration only consists of reporting latitude, longitude, and elevation of your site to the company. Data is sent daily through fax or e-mail. This makes the interface with E-Weather dependent on your computer or fax machine, so this could vary. Additionally, E-Weather is a forecast. All of the other systems report what has already happened, while E-Weather can give you a head start on the upcoming weather.
Forecasts are also a drawback, because forecasts can be wrong.
The quality of forecast data is very good for temperature and relative humidity, but not as strong for precipitation and leaf wetness. E-Weather does provide actual measurements for the past 24 hours. A drawback for E-Weather is that you must have a fax or computer, and the knowledge to use the computer. No single system is the right choice for everyone. Whether or not you plan to use a computer is also important.