Battlefield Play 4 Free is out now in release form, or however you want to say it.
I downloaded and tried it out. It's not bad, though it's sort of jittery on and off. I don't know whether or not I can blame my connection or the game. Otherwise it's not bad. It reminds me of older battlefield games, just because of the size of the maps and the inclusion of planes. It's not taking forever to get into a match like it was before. My only real complaint is that you can't access the options menu if you're in a match. I entered a match, and my mouse sensitivity was too low. I had to leave the match to adjust it, got back into another game, and it was too high. Leave game, adjust sensitivity, and finally in a game and set with a useable mouse setting.
I'm sort of liking the upgrade/weapon system they have. You gain silver coins through playing, and gold coins are bought through an online store. You can spend a small amount of coins to unlock a weapon for 1 day, or a little more for 3 days, or more to unlock it forever. I played 2 games, and that gave me over twice what I needed to unlock the P90 for a day. I played one more game and made up that amount, and bought an MP7 for a day. I noticed though that there's at least one weapon (UMP for engineers) that can only be bought with gold coins. Clothing and such looks like it's only gold coins, but it also seems to be purely cosmetic.
There's also a skill tree unlock system. You periodically gain skill unlock points, which you can use in WoW-esque unlock trees. Some examples are the ability to see which direction you're taking damage from, an on-screen indicator when a grenade lands near you, the ability to sprint faster, climb ladders faster, more ammo for your rocket launcher, etc. I didn't even realize it at first while playing, but a lot of the standard CoD/BF stuff you might expect is stripped out and you need to spec for it. You also need to spend talent points to learn how to drive tanks, helicopters, and airplanes.