I have pretty much stopped buying mags now, the only ones I get on a regualr basis are Fast ford and Performance ford.
Most articles I find are too dumbed down, and rarely give enough depth of what has actually been done, and end up as a long worded spec list, with a bit of background about the owner etc.. I do love the tech articles by Stu, as they are well written and interesting to read.
I suppose the biggest problem with a one-make mag is trying to keep finding interesting and new things to write about that will appeal to the target audience.