I think generally there's 3 cons to having a 2nd (or more). It's double the $$$, more time, more energy.
Actually, there's one more. We initially brought Zoey to be Magnus's playmate. They both prefer human playmate. But they do play together from time to time and it's so precious to watch! Also, even though they're not the best of friends, they do consider each other as a pack.
When it comes down to it, I have absolutely no regrets of adding Zoey to our family. And honestly, Zoey was easier b/c by the time she came, I had more knowledge about how to take care of them.
With all that said... GO FOR IT!!!!!!!