I pre-ordered a copy for the same reason (Boros is lacking IMO), but I doubt I will even test this card. There's no real play to it. It encourages aggressive decks I guess, but it's not like this is something you have to push in this color combination. When you are in a winning position, it's a 7/7 flying indestructible creature for 5 which is all fine and good. When you aren't though, it's a gimped Serra Angel that requires two colors. Feels win more (maybe it's just super efficient closer)? I suppose it helps you race Titans and what not. It goes back to the urgency prevalent in the game now. Like once you get to 5 or 6 mana it's like MUST WIN THE GAME NOW. I don't know. I just dislike designs like this but I'm old school.
I am not necessarily a fan of the design, but I'd just like to point out there are plenty of board states where your opponent is at 10 or fewer life points and you are not in a winning position at all. Indestructible 7/7 sound kinda iffy though (design wise).