Yep, VGTech is probably the best and most reliable source when in comes to resolution and frame rate analysis, but they don't pay too much attention to other possible differences like settings and whatnot. I really love that they always leave the stats for eveone to see the exact differences in performance, though. DF and NXG are more in-depth analysis, but even they miss some details at times.
Unpopular oppinion: I like ElAnalistaDeBits too. Sure, he's made some mistakes in the past (he always wants to be the first to show us his comparisons and he probably should take a bit more time), but Rafael (that's his real name) is a very nice guy and I'm sure any mistake he could make is unintentional. And usually his analysis are not that inaccurate to be honest, look at this one for instance, the results are essentially the same as VGTech.