They have nearly identical clock/boost specs:
Base Clock: 1266 MHz (OC Mode); 1228 MHz (Gaming Mode)
Boost Clock: 1506 MHz (OC Mode); 1468 MHz (Gaming Mode)
vs
Base Clock: 1252 MHz (OC Mode); 1227 MHz (Gaming Mode)
Boost Clock: 1506 MHz (OC Mode); 1468MHz (Gaming Mode)
So the fanless model has an insignificant edge. Other than that, you'll need to decide if fanless will get too hot in the enclosure you'll have it in. If in doubt, get the model with the fan. Also, the fanless model is bit wider if that matters.
Amazon has them a bit cheaper if that matters:
https://www.amazon.com/ASUS-GeForce-GDDR5-Graphics-GT1030-2G-CSM/dp/B0716ZH99K/ref=sr_1_5?s=pc&ie=UTF8&qid=1497991884&sr=1-5&keywords=gt+1030
https://www.amazon.com/GIGABYTE-GeForce-GV-N1030D5-2GL-Computer-Graphics/dp/B071DY2VJR/ref=sr_1_1?s=pc&ie=UTF8&qid=1497991884&sr=1-1&keywords=gt+1030