I am a fairly newbie but, the Dayton setup itself should be fine (heard all good things about them too). I believe the question comes in with the amp on them. I think that 70wrms on a 3way may be too little and push them to a desent potential. If you have the 70w and you split it 3ways, you are only giving each driver about 25wrms. That may be sufficient for the tweet and maybe the midrange but definitely wont be getting front bump out of the 8s (wont be enough).
You want to look into giving them closer to 100-125wrms and I believe it will definitely raise the volume and sound along with help the staging in your fronts. As for the backs, I wouldnt make a 3way, maybe a solid 2way. Remember your backs are merely to surround you (Dayton 2way).
Bostons are good but they do lack that added power that people are looking for especially for the subs. Have you thought of Hifonics, they give you some power without the deep pocket.