I am thinking about getting a BCT15X. I have a BCT8 - thinking about exchanging it since I found the BCT15X for the same price online. I use the scanner as a home base unit - listen to local, surrounding counties, Air, Weather, News, and all the preprogrammed stuff. BCT15X has 9000 channels. The features I am not familiar with are "Location Based Scanning and Close Call Feature". What do these mean? And would it be a good idea to swap scanners?? Thank you!