PS+ is a great deal and i'm glad it's carrying over to PS4. As for the "paid content" comment, I don't see it that way... A 1 year membership is $50 (less if you find a deal) which is less than a new release. The membership gives you access to more than just "free" games. Technically the games aren't free, and are more like rentals since you lose access to them if you membership expires, but you get access to a bunch of them, covering the cost over membership and then some.
In addition to the games, you currently get the cloud saves, and PS+ prices on the PSN store and if during a sale, these prices are usually really good.
Currently the BIG difference between PS+ and Xbox Live Gold is that you really don't need to have PS+... Sony is not locking non PS+ gamers out of anything, just giving them more in return. Granted this will change a little with the PS4 since PS+ will be required for Multiplayer (am bummed a bit about this decision), but even with that blemish, it's still a better service than Xbox Live Gold.
A glaring example (and this will apply for the Xbone and the PS4) is that you NEED Xbox Live Gold if you want to watch Netflix on your Xbox, but don't need PS+ to watch Netflix on your PS.