This is only one OVA so i'm gonna keep this pretty short and sweet. I already did i review for the first season so there's no need to go over it all again :p
Sora no Otoshimono is a great anime, I had alot of fun watching it and this OVA is nothing special but however it is another edition that adds to my enjoyment of the show. Right away i'll say that I liked how the episode specified where this episode takes place in the story, after episode 13. There's no action and no deep emotional moments, but there's still the same light hearted echi comedy that there is throughout the series. There were alot of funny moments and this felt like just a regular episode. You could tell just by watching that they had fun when they made this episode it definitely shows. It goes without saying that the animation and sound are on point just like it is in the other episodes. It's nice to see some bonus content with some entertaining unique characters and that's what this OVA is good for. Like I said this felt like watching a normal episode and I enjoyed it just as much as the show itself. The ending had a nice touch to it as well which was good, it didn't feel like complete filler.
Overall this was a great edition to the show, it was funny and I enjoyed watching it. I'd recommend watching this if you're a fan of the series, or the first season alone for that matter.
Hope this review helped, give it a thumbs up if you agreed! (: