It seems like a piece of history I was a little late to the party to. By the time I first picked one up, it had become a thin magazine not a whole lot better than PC Magazine.
That was the go-to magazine if you were building your own machine. It's heyday was sometime in the early 1990s, when PCs were starting to branch out and become consumer-oriented items. But in the 386-486 era - that was an insane magazine to peruse (big too!).
Really, one could say it marked the end of a particular era - that of hobbyist machines. While it was a technically oriented magazine, it did cater to those who wanted to build their own systems (maybe not from the component level). Once the PC became something you could easily pick up just about anywhere, it started to get thinner and thinner, then finally disappeared.
That was also the end of the "mom-n-pop" style PC computer parts stores. There are a scant few that linger on today (mostly they sell used machines refurbed or rebuilt - though some have gotten into building and selling retro machines, sometimes for steep prices).
If I remember right, it had just enough editorial material to squeak past the line that divided the less-expensive postal rates for literature from the more-expensive rates for advertising.
Also the Ken Gordon Computer Shows.
I actually upgraded/built a system a few days ago but even I'm pretty much out of doing that sort of thing. Wouldn't have done it if it wasn't a Linux server thing and I already had a number of parts.
That said, even at the end, it was still a cut above most other computer magazines on UK newsracks.