I've been pretty happy with the seven-year performance of my Oregon scientific 433MHz wireless. I have a remote sensor in my greenhouse, another in the basement, and the base station set up in the master bathroom. The distances are about 40 feet and through an interior and exterior wall, and it keeps the signal consistently. The one that I have just stores the min and max temperatures/humidity for three remote sensors. For data logging, I might look at the Model # WMR200A. According to its manual, even at 1 minute data intervals it can store 19 days of data, and then download via USB to a computer. At 15-minute data intervals it can store 291 days.

I've been using the Taylor thermometer for a couple of weeks. Despite its flimsy appearance, it seems to be functioning well, as far as I can tell. When I've compared its readings to those listed for nearby weather stations, they agree within a degree or so, in a consistent direction (for example, my high and low are always about one degree cooler than those recorded at a station about 20 miles southeast). It seems sufficient for my purposes. Mark, I think your suspicions are right; quality control on the Taylor may be inferior to its earlier models, but in any case you got a bum lot. Another note: The site I mentioned says that among "analog" thermometers, it prefers mercury, as generally more accurate than spirit-based ones. Personally I'd never allow a column of mercury housed in a fragile glass column anywhere near my home or garden.

I've had a LA Crosse WS-9625U-IT for several years. It will accept 3 sensors. The manual recommends alkaline batteries, but I believe I've read that for extreme low temperatures, lithium batteries be used in the sensors. It's been so long since I've changed the batteries in mine, I can't remember what kind I have.

I don't have an alarm, but I do have a wireless transmitting thermometer, that allows me to see the temperature in the greenhouse from my favorite family room chair. I replace batteries every spring and it's lasted 3 years now. http://www.windandweather.com/wireless-thermometer-with-color-display.htm?aff=6158&gclid=CNC46NLg6c8CFQqDfgodLtUBhw