We did a bit of pricing for our preferred features. The decision to go with the RFu-328 over the URF(XRF with USB for easy flashing) was pretty easy once the documentation became available online again. The RFu-328 is just an XRF paired with a little Arduino. For just a little extra, you can program your sensor's "personality" over the air without ever touching the radio firmware. We also came to the conclusion that it may be worthwhile to have a common environmental sensor module(temperature, humidity, etc.), rather than having every sensor use a separate RFu-328, regulator, battery set, and case. Secondary sensors, like moisture sensors or CO2, are, well... secondary. Some sensors are required less often as a part of a grow room, need to be able to be moved around the space, or can be used several times in the same room. I.e., the common sensor would handle macro-environmental sensing, secondary sensors would handle micro-environmental sensing and special cases. Still haven't been able to find out if the Slice of Radio can escape its intended protocol to switch outlets, but with the 433 Mhz transmitter/receiver kits running around $5 it's not a proportionally large issue.
More diagrams and an explanation of how these sweet-and-simple serial wireless protocols work are on their way.