I like the PSR-600 so much I bought a second one to install in our "out of town" car (the one we use to travel). San Francisco has been using a digital "Smartzone" Motorola trunking system for about 5 years now. As the FCC narrow band deadline of 2013 approaches expect to see more agencies/whole counties in the Bay Area employ similar systems. This is true in most of the large metro areas in the U.S. as well. The PSR-600 is capable of narrow band operation right now and the low cost radios are not, even the new ones being sold, and they can't be upgraded to do so. The purchase of one of the $500 models right now will save money in the long run.
The PSR-600 has a great feature that I'm finding very useful, really essential right now. Some agencies are already employing narrow band radio systems so they will be compliant with the upcoming narrow band requirement. When you have a mixture of narrow and wide band signals the volume needed to hear the narrow band signals will blast you out of the room when a wide band frequency is received. The PSR-600 has a channel by channel option of employing an "audio boost." Using that on the narrow band channels allows you to set the volume to a level where you can hear both. In my neck of the woods I am always scanning the feds, whose narrow band mandate started in 2005. I had to sit next to the radio and adjust the volume so the CHP would not blast me out of my seat while just barely being able to hear my favorite federal agencies. I often found myself frequently adjusting the volume and this made listening further than 5 feet from the scanner impossible. The PSR-600 allowed me to listen from other rooms and over the remote speaker in my garage.
The narrow band requirement coming up in 2013 does not just affect the public safety portion of the land Mobile radio service, but business use as well. VHF/UHF ham radio is the only portion of the land mobile service without this upcoming mandate. Listening to most radio services will be problematic with an older scanner after 2013.
Whether you buy a Uniden or a GRE/Radio Shack scanner is somewhat like the Coke and Pepsi thing. However, most agree that the digital audio on the GRE scanners is better. Whether the upcoming new Uniden scanner model will change this is not known right now. For me I had mostly Unidens until the PRO-92 came out. Since then I've stuck to the GRE manufactured scanners including the PRO-2067, PRO-96, and PSR-600 with only one exception. One reason is that the StarrSoft programming applications allow me to transfer data between the files for each model. That saves a huge amount of time when I write and revise files for each scanner.
I was hugely disappointed with the BC-780 scanner I purchased for base station use sometime around 2003 or 2004 and the PRO-2052 Uniden manufactured base station I bought in 1999 or 2000. I still have my BC-210 and three BC-760's in use around my house and in one vehicle. The BC-760's was one of the best scanners ever made, but then my PRO-2006 has been regarded as the best scanner ever made. I really like the BC-235, the first trunk tracking scanner, I purchased in 1995 or 1996. A great little radio, but without narrow band, digital, and alphanumeric capability. Those scanners work well in my local, mostly non-trunked, listening area, but in the Bay Area would not be too useful.
One thing that can probably be agreed on by everyone is to stick with one brand or another as much as possible. I'm very comfortable with the StarrSoft software and the operation of the GRE scanners as each new model is not a huge change from the last one except for some new features. This makes the learning curve shorter and a whole lot less challenging for me.