Leave both activated. It's worked the best for me. I'm pretty sure that all but one ad will be linked to the HB program, and the remaining ad will link directly to your adsense account. You'll rarely see an adsense click, trust me.
Hubpages adsense account has a higher cost per click because they have high standards when it comes to ranking their hubbers. High cost per click = more money than your personal adsense account.
In addition, HP ads are better, more engaging, and relevant.
If you're looking to make more money, start a Youtube Channel, Facebook fanpage, Twitter account, and link all to your Hubpage account. Stay in the same niche and use the same name on all accounts if possible.
I really should write a hub about this.