Pros and Cons? Use them both?
Use them both if you are able. If you are not able to use them both, use bitcointalk.org.
actually my question for OP mate is why need to use altcoinstalk when everything we need is already in Bitcointalk?
there are so much happening here from bitcoin market to thousands of altcoins around the globe so i guess it is just a waste of time to consider using 2 unless you are a typical BOUNTY HUNTER that only uses Sites for bounties and not for investings .
I only glimpsed about altcoinstalk and most of them are bounty hunters who go there so for me about all the information and ANN coins, of course the bitcointalk forum is the most complete with lots of traffic on this forum indicating that there is no match and this forum is indeed a lot used by seniors who used to be the creators of the first coins on average, therefore I am not interested in the altcoinstalk forum even though I have teleported my bitcointalk account to altcoinstalk.