Nince makes a great point about people who just purchase from Costco, stick it wherever, connect it to WU, and forget about it. Unfortunately, some people have less pride about data than others. In my neighborhood, I am sandwiched between an Ambient station and an Acurite unit. Both stations have their flaws. The Ambient's barometer malfunctions every-other upload. The Acurite runs very hot during the day (and gets kicked off the map regularly) and runs very cold at night. I had a LaCrosse unit (a 2813 from Costco). I took the time to get a mast for the anemometer on the roof. I also purchased a radiation shield for the hygrometer. The rain gauge, I got a shelf and placed it on the top of the fence post, level, with bird spikes. My data was generally good, especially the temperature/humidity/pressure. I have been online with a Davis Vue for the last month, but my data is suffering because I chose to sacrifice temperature data with better wind accuracy. In the morning, my temperature shoots up when the sun rises and usually levels off with the other stations nearby by mid-morning. During the afternoon, it runs equal to or sometime slightly lower than neighboring stations. My CWOP ratings, which were very solid with my LaCrosse unit, are in the toilet somewhat with the Vue. The all-in-ones are a pick and choose compromise.
So, I think everyone in this thread has great points. We do not really know how others data is unless we actually see what steps they went through to mount their sensors. Based on my personal analysis, I would look to avoid any all-in-ones going forward, including the Davis Vue. It is what it is, but I did not have the money for a VP2. I will look to get that station sometime in the future so I can site the sensors appropriately.