I just received my 396 yesterday so I dont have a lot of experience with it yet.
I do love the digital sound of ISP though!
Right now I have PU Airport, Municiple Services (street/water), Schools, and Weather on the 246 and have ISP, Public safety (LPD, WLPD, PUPD, Sheriff, LFD, WLFD, PUFD, TCFD, EMS, TEMA) on the 396.
I found a site that list a bunch of frequencys, but I wouldnt have a clue as to how to program them without pulling them from the database with ARC. >
http://www.perfective.com/nick/tippecanoeco.htm < I might have to play around with a few of those though.
Nightfox when I first got it I did a close call search, and it picked up lots of weird stuff around 106.xx -107.xx not exactly sure what it was as I didnt stick around was in too much of a hurry to get my systems loaded. Digital sure is cool - but I wouldnt put them in my car - Indiana has a law on file banning use of them in mobile applications. If you get caught with it in your car they might confiscate it.