All of these companies are top notch including Def Tech. It would be a good approach to determine your budget, what you want to achieve, sub size and appearance, how much output you require to fill your room, and anything else that's important to you. This may narrow down your choices to consider and find the sub that is better for your needs.
The subwoofer forum is a good place to get a wide variety of opinions and the individual subs' home-thread as well. I would advise you to phrase your question without the wording "which one is better". That may not get you the input that you're looking for