I've had some issues getting the device to behave so I can develop code. I don't know if it's on my end (MacBook Pro 10.10.3) or the device itself. In any case, application development has stalled while I work through the issues (as time permits). That being said, the seller has provided outstanding support, going above and beyond what's normal.
There is a lot of ESP8266 documentation available--almost overwhelming--and it's a bit of a challenge to get to the bottom of the issues I'm facing, recognizing I am a newbie with regard to the ESP8266. For the seasoned ESP8266 developer, I'm sure this seller would be a viable source of product, as he has been with other products, too.
This is a great i2c sensor when you need humidity along with temperature. My only concern (and it likely has nothing to do with the breakout board) seems to be the accuracy of the temperature reading. We're finding some of the sensors readings about 1.5 degrees high as compared to the average of 4 Precon 10K NTC thermistors and other devices. That being said, we'll continue to purchase these and introduce an "adjustment" to the reading as necessary.