It's that way with cordless phones, too. The advertised ranges are seldom equaled in the real world, and the same phone may behave very differently in two places, or even in the same place on two different days. Cordless phones are generally able to maintain an existing conversation at a greater distance than they are able to start a conversation, and can ring at greater distances than they permit talking. In the same conditions, while using a digital phone, you will probably hear clicks. Near the range limit of any cordless phone, slight movements and changes in position can make a big difference in performance.
Vegetation affects range.
If you can get the base up high, you will probably get more range. The numbers below DO NOT indicate the maximum range for the specific phone models, just their relative ranges in one place on one morning, in a typical suburban environment with cool, clear weather. We have no way of knowing if the phones we tested were typical of all others of their specific type or series, but we assume they are. Each phone base was placed about one foot inside a window, about six feet above the floor. Only one phone was connected at a time.