I have Version B and like I mentioned before, even with a polarity switch it sounds like hot garbage. I opened it up and it is a TINY amp which makes sense since the power wires to connect it look like they're 16 gauge. This looks like the product they copied for Version B:
PWE-S8 | Compact 8" Powered Subwoofer and it's only 120 W so you can probably assume the Version B sub is even weaker.
So...all that being said, after I saw the person who fit the 8" Rockford P300 into the space for the sub I was going to order it but your comment had me reconsider so I got the 10". Honestly, after having two 12" subs in my car as a young driver I thought the 10" would be weak like you said. Ultimately, the 8" that fits in the space would have been more than enough. The 10" has a 300 Watt amp built in and is surprisingly loud. Honestly, it is a little much when it comes to balancing all of the frequencies, thankfully they include the 'Punch' remote.
I recommend anyone here gets the harness only and taps the wires for the 8" Rockford sub with built-in amp. It will be close to the same price and SO much better bass. With the awful Hansshow sub the door woofers were putting out better bass than the barely their pounding Hansshow crap. Do NOT waste your money on the Version B sub, go with the harness only or buy a better sub, like the P300-8, somewhere else. Sure, you could get the Version F with their OEM-like sub but they still don't tell you the power, only a silly YouTube video with paper on the subwoofer cone, and it is very expensive. The 10" P300 is LOUD and fits in the sub trunk while the 8" will fit in the original sub location.
After suffering through being a beta tester for their harness as well as their awful sub, I am bitter but now satisfied as I have resolved all of the weaknesses of their half-baked products.