One of the main problems with Kraken is that they purport to be US-based all over forums and reddit when in fact they are not. They have offices in San Francisco but their main banking relationship is with Fidor in Germany. This makes it difficult for US traders to use the site, hence their high Euro volume. Unfortunately, it doesn't seem like this issue will be resolved anytime soon. As far as US based exchanges go, I use CoinMKT. Their volume is low, but that can be changed if US users begin to migrate there. I believe they're listing dogecoin sometime this week, that might help.
Kraken is a good site for european traders. It's not the best for US, no matter how many times their reps say so in threads.