Florint, ChemE makes a good point about the RFM69W & RFM69CW 13dBm transcievers.
Myself, I use multiple Moteinos w/ RFM69CW for my pool control.
I don't have to worry about running on batteries but extra transmit power does not help when you can receive without issues. I'm in a residential neighborhood with a somewhat noisy power line in the back yard. Yet, even with the background RF noise, I see good signal levels inside the house from the back yard (over 100-ft away).
As a licensed radio operator, I'm for using as little RF power for as short a time as possible in order to reduce the possibility of interference to others.
If everyone uses the lowest power/time usable then everyone experiences the least interference.
However, if one person transmits at high power for long times then everyone experiences interference.
Along the same line, using TomWS/Felix's ATC will maintain reliable signals at reasonably low transmit power (and supply current) even when background noise changes.