Here is the first release of the dht11_spi library (also available on PyPi). This release supports both DHT11 and DHT22 and uses the SPI bus to receive the binary data from the device rather than the legacy bit-banging method. On an idle system I regularly see 100% success rates sampling at 1sec intervals (for the DHT11, 2sec for the DHT22). On a busy system I experienced 93% success which is vastly better than the legacy bit-banging DHT11 libraries.