Stick with bitcointalk whether its Bitcoin related or Altcoin related talks. Most projects prefer to run their bounty in this forum. But in terms of information almost the same its like a mirror of altcoin section of bitcointalk
There is no mirror between Altcoinstalk and Bitcointalk altcoin section at all.
Altcoinstalk is full of nothing but nonsensical spam. There is also a lot of spam on Bitcointalk, but you can find a huge amount of valuable information here, no chance on Altcoinstalk for that.
Remembering those days where there some bounty where altcoinstalk was just starting and i agree that place is really infested with lots of spam.
Same goes into this altcoin board of this forum itself but i agree on the point you had said that there are still valuable things that you can sip on here.
If you are really in torn on which one is better then why wont check out for yourself and tell on which one does suit out your interest?