I am looking to get either a BCD456HP or a SDS100. I am new to scanners, but not radio. Have been DXing AM broadcast band and listing to shortwave radio here in North Carolina for many years. Also am familiar with programming languages, using databases etc. for work as a Mechanical Engineer. So, I have the technical aptitude to learn how to use one of the units, and to enjoy learning about its operation. Most of my listening will be from home, but also some on the road and at camping sites that I like to go to. I vacillate between the two units. Would a 486 serve me as well as a SDS100, or should I just spend the extra for the SDS knowing that I can install added features as time goes on that perhaps are not offered for the 456. The zip code feature is a real plus to me, as I can get either unit operating immediately while learning finer points of tuning the unit over time. I am looking forward to any advice you can offer and it will be greatly appreciated.