Microsoft's Xbox division doesn't follow anyone's lead. Xbox Live has been the "gold" standard for console online gaming for more than a decade now, and, as long as you're willing to pay the yearly fee, you're typically getting the most robust online gaming and apps available.
Sony has been slow to roll out comparable online functionality, more or less giving up on some features until PS4 rolls around (like cross-game chat). But what they lack in features they make up for with the PlayStation Plus Instant Game Collection. By giving subscribers free games on a regular basis, Sony has flipped the script, giving subscribers value they can see. After all, "Free games!" is a much better sales pitch than nebulous "great features." This has forced Microsoft to change their tune and follow suit, at least temporarily. Now that Microsoft's Games with Gold service is in full swing, how does it stack up to PlayStation Plus?
The core difference between PlayStation Plus and Games with Gold is in the definition of "free" games. PlayStation Plus offers games for free as long as you download them when they're being offered and you then maintain a membership. Stop paying and you lose access to the games, but you can always starting paying again later to get your games back. With Games with Gold, as long as you have a Gold account when the game is available and you download it in that timeframe, you keep the game forever, whether your account lapses or not.
That's a distinct difference in approach, as Sony is offering more of a subscription service while Microsoft is just giving subscribers free games they get to keep forever. If a subscriber decides to stop paying for Xbox Live Gold, they won't lose their games as a result. For those who like to maintain their games over the long-term, years after the console is still relevant, Games with Gold seems like the more reliable offering.
The problem is that the quality of the games and frequency with which they are released can't even be compared. PlayStation Plus, from a pure game quality standpoint, is an infinitely better value, offering subscribers games that were released within the last couple of years. Games with Gold's offerings -- Fable 3, Defense Grid, Assassin's Creed II, and Halo 3 -- are ancient by comparison.
The value of PlayStation Plus is taken to an even greater extreme when you consider that free games are currently being offered across both PS3 and Vita. Owners of both, especially early adopters of PS Plus, most likely have a huge backlog of free games to play. The Xbox offerings, by comparison, have a lot of catching up to do.