Definitely doesn't have an aluminum body! It has a composite body, your info is wrong. I also think your comment is hilarious since a few posts before his you say the nasci is the best 100 dollar reel. Do you own and fish every 100 dollar reel?
Anyway....I've owned both, the nasci and the new daiwa bg, both 2500 size. The new bg is an awesome reel so far for the price, if it performs good for a few more months I will be buying more. It solid, smooth, and has a really good drag. The nasci has a lot of flex in the stem, and I guess shimano STILL hasn't resolved the binding problem because the first day I fished in a heavy rain it started binding by the end if the trip. It does have a really good drag though like all shimano's.