I like it. Which is a good sign, considering I hated Eternal Blaze at the beginning of A's, but really liked it near the end. For some reason, it reminds me of a Gundam song, but considering all the comparisons between Nanoha and insert-mecha-series-here, it's a good thing. Someone in the chatbox (I forget who, as I was probably half asleep at the time) said it sounded "more like an OP than a pop song used as one". Thinking about it, I have to agree. It sounds more mature than the previous songs, fitting with the ten-year aging of the protagonists. I can't tell if the clapping in the background is from the audience or actually part of the song, but it really adds to it. It's not glaringly "missing something" like I thought Eternal Blaze was when I first heard it, and the beginning reminds me of Brave Phoenix, my favourite Nanoha song.
This is the only video I could find that uses the song. Putting the previous season's OP animation over it, now that's original. Sorry.
I debated using a different picture because I've already used a Nanoha picture on this page, but... no.