As other people have said, it came out on bd and subbed about 3 weeks ago.
About the movie (lots of spoilers, so don't read unless you want them): the first 40 min (well excluding the first 2 min) are all recap with some input in from the new character. After that, you finally get Zeta's arc. The beginning part of zeta's arc is told fairly faithfully to the manga, so if you read that, you'll know what to expect. (at least accurate to my memory) Things start changing after Zeta disappears the first time. Basically they cut out the maid scenario and skip to the night scene with Tomoki and Nymph. After which, they cut short Nymph's development and change zeta's power (probably to make an easier to explain fight scene.....). Oh well, afterward you see the fight with Zeta is completely changed with no Aphrodite!!!!!T_T Then the movie ends with a little bit of the conclusion cut.
In the end, I thought the movie was decent, it really caught the emotion Tomoki and Zeta had (probably the most impressive thing they did), but animation was only the same quality as the TV series (which is a little above average, but not much more) and the fight scene was lame imo.
Advice:If you watched the anime and read the manga, feel free to just watch the first 2 min and then switch to the 40th minute. In that way, the movie will feel like a 40min ova that you can try out without feeling like you used that much time.