It's the most accurate poll in 2012, pretty similar to USC/Dornsife in that regard.
There's been a sharp divergence of online pollsters and live interview pollster this year. The average difference is about 4 points. The 'rolling panel' ones like LAT and IBD are the most favourable to Drumpf.
One reason maybe that he has a much more robust presence online, making it harder to select the samples. With the notable exception of Michigan, a state with horrible data to poll in the Dem primary, live interview polls have been pretty close this cycle so there's no reason to think that they are off by 7/8 points.