Well, there are positives and negatives to every firewall. One might not be better than the other, but using both can protect you even further than just a single hardware firewall. Hardware firewalls can protect you without much configuration, which can be both good and bad. The good is that it can protect and hide you from the internet world. The bad is that the firewall may allow information to get back out that you don't want out on the internet or to a hacker.
Software firewalls are good at limiting information that may leave your computer. If you get a virus that is a DOS attack, the firewall would recognize that it's a new program trying to send information out of your computer. The hardware firewall wouldn't recognize this. The software firewall adapts to your browsing and internet habits better than the hardware firewall. It will ask you if you want this program to access the internet (if it's one of the better ones).
I am most concerned about my information leaving my computer, but I also don't want my computer exposed to the internet. The best solution for me is both.
Here's a link to understand more about firewalls Firewall Information