As TXTBOOK said, I have pretty good knowledge of the unit, as it is my neighbor that designed the whole thing and I work for him.
The need to plug in the unit really isn't that much of a hassle as it just goes straight into the cig lighter and runs off the aircraft's power. If you think you'll want an external battery, we do have those for sale.
Weather is soon to come, if we were to put, lets use XM weather, on the unit, it would drive the cost up immensely. When ADS-B becomes available, we will in cooperate that into the unit for weather.
If you have any questions, ask them here, PM me, or call us 1-888-200-5129