Hey hey hey, no fightin!
I am sure people who haven't tried Tamiya primer would find this thread useful.
BTW, I just used Tamiya's "fine" primer immediately followed by Gunze's 1200 "fine" primer (I ran out of the Tamiya), and guess what? There is a noticeable difference - the Tamiya is satin and very smooth, the Gunze is flat and has a slight texture. I used them on the same model on similar surfaces. Bottom line? I'm buying Tamiya from now on.
Those who claim cheap big box primer is just as good may be right, but will stick to Tamiya. Someone needs to do a "shootout" comparing primers across the board. That is the only way to settle it.