I have the Zephyr PWS 1000 (FineOffset) and really like it. I picked it up this winter based on recommendations here for an inexpensive starter station. I've been using Cumulus for the software.
Yesterday I took the station down and took it apart because the rain gauge wasn't working. I never expected the issue to literally be a "bug in the system"! With said offending insect and its nest removed, it's working fine again and is set back up. I love being able to look up temps, rainfall, etc., esp. if I'm away from home. I can just check out Wunderground and see how much rain, etc.
If I do it again, I might go with the one-wire system or if I have plenty of extra $$$ the Davis, so that I can add additional sensors for the greenhouse.