SIGFOX has certain limits (outside of theoretical and practical bandwidth restrictions) placed on it. radio-electronics.com (http://www.radio-electronics.com/info/wireless/sigfox/basics...) states up to 140 messages of 12 bytes per object per day, with a throughput of up to 100 bytes per second.

The Things network, on the other hand, seems to supply its services openly and freely without limits, using the LoRaWan spec. Semtech (http://www.semtech.com/wireless-rf/lora/LoRa-FAQs.pdf) says it provides between 0.3 and 11kbps of bandwidth, so in theory your speeds can be anywhere from 3x to 111x higher.

I'm not an expert but a big difference is packet size: Sigfox is limited to 12 bytes, while LoRaWAN is up to 256 (iirc). Sigfox also imposes a max of 140 messages per day. Also, the governing body of LoRa is open (lora alliance), while Sigfox is closed. In general, the LoRaWAN approach is more open, with most if not all of the infrastructure being open sourced.