Mine is 50 degrees low if I am cooking in the shade, in the sun its close..
I really think with the Akorn you need some form of digital thermometer even if your factory one is accurate for low temp cooking.. I bring mine up to temp and close vents down based on how fast the Maverick is going up.. With how slow the factory is your temp can be climbing or fire going dead and not realize it before you have problems..
I would look to Maverick and Thermoworks and find a digital that meets your needs and your budget.. I have an ET 732 and am very happy with the ease of well running Akorn you can get things done and monitor the cooker.. Additionally with our cold winters it allows me to sit inside while the cooker cooks..