The upsides are that after three months all of my articles become free. Since Vintage technology doesn't age that quickly, almost all of my old articles are relevant for at least some nugget of knowledge. Alternatively, subscription for a month isn't that expensive. For $5 you can read not only me but Flores, Wakefield, Rizzo, Chapin, etc.
This article is less about technology than Steve's love for the game, and will be just as relevant when it becomes free.
The premium subscription really is worth it though. For a couple of dollars a month you get to experience the thoughts, theories and reflections of people who devote themselves to this game (its not so much about getting hot tech, since most of the lists can be found here). Plus, you're premium dollars are making it possible for people to devote more time to thinking and writing about the game, and therefore improve the overall quality of MtG discourse.
Compared to the cost of a newspaper subscription ($.50/day) its a great deal. I get far more enjoyment out of my SSG subscription than the SF Chronicle (the NY Times might be a different story, but its more expensive anyway...).
OTOH, Silvestri's articles are still free (for now), and he's a great writer also.