With the WS-1002-WiFi, you are paying for the DISPLAY, NOT sensor accuracy, build quality, long term durability or sensor quantity! The outdoor sensor unit used in the WS-1002-WiFi (WS-1000-ARRAY) is the same one used in the WS-1400-IP which sells for roughly half the cost of the WS-1002-WiFi. The difference is the WS-1400-IP has NO dedicated display BUT includes the ObserverIP receiver which feeds your station readings to WU and Ambient Weather networks and makes your station readings available on your local area network (WiFi) regardless.
The WS-2902 Osprey is a new design with an improved outdoor unit, same sensor suite (temp/humidity/anemometer/wind direction/Solar/UV) as the WS-1000-ARRAY AND it has a dedicated color display! FYI, barometric pressure is read on the indoor unit be that the dedicated display OR the separate indoor temp/humidity/pressure sensor that come with the stations lacking a dedicated display.
As to why the WS-1002-WiFi is still priced where it is begs for an answer, but technically there is NONE! There is ZERO requirement for a display if you use a computer and mobile device routinely. Is a dedicated display nice, yes, but certainly not a requirement. Originally I went with the WS-1400-IP as I did NOT value the display sufficient to pay double. A nearby lightning strike took my WS-1000-ARRAY (outdoor sensor) unit out, so reading between the lines, I ordered up a WS-2902 with expectations of my ObserverIP receiver being able to receive the Osprey. I was correct and the setting needed is the mystery WS-1600-IP. By ordering a WS-2902, I got the color display that comes with it and while nice, I still would NOT pay much extra for such.
FYI, the WS-2902 display unit reports to WU, Weather Cloud and Ambient Weather networks, but you do NOT have to activate the WiFi if using the ObserverIP unit. I prefer the ObserverIP unit as from it I can feed my MeteoBridge (sold as WeatherBridge by AW) which in turn lets me fed a plethora of weather networks, NOT just the ones that AW ordains.
I am finding the Osprey's humidity sensor to be more accurate, its anemometer starts up at .2MPH vs 3-4MPH on the WS-1000-ARRAY, the wind direction is better dampened, it has an easily removed rain funnel (ie cleaning without disassembling the entire unit), it has uses black plastic for the rain funnel/anemometer/wind vane to better melt snow and ice and overall it is simply a nicer looking unit installed (IMHO).
The one thing that some may point to as a downside is that the Osprey uses non-rechargeable backup batteries (lithium recommended) vs the WS-1000-ARRAY's solar recharged batteries. The Osprey IS solar powered during daylight hours. At least according to Ambient Weather the Osprey batteries should last 1-2 years while the WS-1000-ARRAY recommended replacing its rechargeable batteries....wait....every 2 years, so a wash!