I'll throw in another vote for the X50, or whatever they call it's equivalent now. I got mine a few years ago and just like others have said, if you pay attention and don't expect it to save you without fail, it will pay for itself in no time. I don't do much driving, but when I do it's usually between my parent's house northeast of Cleveland, and OSU. Thing is a fucking lifesaver on 71 and 271, and the range is up there with the best of them.
BTW, don't waste your extra 40 bucks on the blue display unless you really love blue for some reason. As far as I know there is nothing different internally other than the display.