When I looked it up on yaesu, the first difference was the big colour display and the impression it was bigger than the FT-897D. But I was more interested to see the specifications, and here they are:
Feature | FT-991 | FT-897D with internal tuner and battery |
Weight | 9.5 lb (4.3 kg) | 10.3 lb (4.7 kg) |
Battery capacity | --- | 2200 mAh |
Power consumption RX | 1800-2200mA | 600-1000mA |
Impedance | 16.7-150 ohms | 4-800 ohms |
So it seems that the FT-991 is 10 percent lighter than its competitor, which can be partly due to the fact that it does not feature an internal battery. The consumption on receive is also between two and three times higher than on the FT-897D, which is also a handicap when operating portable on battery power. Finally, the range of the tuner is much narrower, which can be a minus when operating portable.
All in all, the conclusion is that the FT-991 seems to be a very nice radio, with a colour display, an USB port and new features, and is a welcome addition to the Yaesu line, but is designed with a different style in mind and is therefore not a direct replacement for my Yaesu FT-897D with internal tuner and battery.