I bought the Whistler xtr-325 and I'm going to return it. The reason? The power on self test is too annoying to tolerate. According to the manual there are a lot of settings that can be changed (page 13), one of the settings listed is "X, K, Ka audio tones one beep during power up", so I spent a lot of time trying to turn this option on without success. So I finally gave up and called Whistlers support number to find out how to turn on the abreviated power up sequence (as well as how to change most of the other options since I couldn't figure it out). The support person informed me that most of the options listed can't be changed, including the full power up sequence. In fact the only options that can be changed on this unit is VG2 on/off, voice on/off, and pop mode on/off. I was on the fence about which unit to get, either the xtr-325 or xtr-420, had I known that the xtr-325 didn't have the ability to change all the options as described in the manual, I would have gotten the xtr-420 instead. I informed the support person of this and asked if I could upgrade to the xtr-420 (and pay the price difference) and his repsponse was to return it to the place where I bought it and buy the xtr-420. I asked, what if they won't accept a return. His response was there was nothing they could do, I would have to work with the place I bought it from. To me this is totally unaceptable since my decesion to buy the unit was based on faulty information from the company. So I will be returning the xtr-325 from where I bought it, however I will not be getting any unit from Whistler to replace it because of their lack of customer support.
Other observations about the unit:
The maximum volume level isn't as load as I would prefer, I could live with it if that were the only problem.
The mode I would normally use the unit in would be auto quiet where the volume drops after a few seconds of warning at the set volume level. However the lower volume that it drops to isn't load enough to be heard over road noise, the ac running on full (it's hot down here!), and the radio at a moderate volume. This isn't a problem with my other rd.
The display gets washed out if the sun is to the side or from behind. This wouldn't be a big problem by itself, but combined with the volume problem the rd becomes useless in the auto quiet mode at certain times in the day.
The only way I could test it is with a road speed sign (k-band) at the airport, the sign was just beyond a curve in the road. I made 1/2 dozen or so trips by the sign with the xtr-325 and with my other rd (a Cobra ESD-6200). I couldn't use them at the same time since the Cobra leaks on the k-band. I put the car in cruise control so that I was driving the same speed for each pass and noted where the car was when the detectors went off. They both went off pretty much at the same spot + or - a few car lengths. The xtr-325 would go off slightly later than the esd-6200 but both gave ample warning. I was a little disappointed by the performance of the xtr-325 since it is a much newer unit than the esd-6200, I would have expected it to have performed better than my old unit, not slightly worse. I haven't encountered any speed traps so that I could test any other bands. As for falsing, the xtr-325 falsed in all the usual places the esd-6200 gives false readings, however the xtr-325 falsed in other places as well. Most of the other false alerts were in the ku band which the esd-6200 doesn't detect. Since the US doesn't use the ku band yet, it would be nice to be able to turn ku band detection off as the manual states you can, but as I pointed out before the manual is incorrect and it can't be turned off.
The only thing I liked about the unit was the windshield bracket. After adjusting the bracket to get the esd-6200 level, it will tilt downwards after a little while (I assume because the suction cups stretch a bit after getting baked in the sun). This didn't seem to be a problem with the xtr-325.