Repair or replace my subwoofer

I live close to the headquarters so I can deliver and pick up pretty easily. 

Looks like they're $750 new so $400 is reasonable if there's no shipping fees. Your other option is to bin it and get 2 subs like REL T5x etc.

Hayward was also close enough for me. Took mine in at 10am and got a call from them by 3;30. Maybe a slow day? I still use mine in the home theater and occasionally in a small PA system. 

The new plate is a bit more detailed with a better volume remote control but to answer your question, yes, a few subwoofers have improved greatly in both aspects but at a price.

The Super Nova benefits noticeably if it's positioned in or near a rooms standing wave bass modes. 

The Nova's lower frequency output exceeds any -6dB sub-bass woofer system.   

I think the question would center around usage. Is it exclusively for home theater? Home theater is a less exacting application where volume of bass is of higher priority. There have been advances in subwoofers in twenty years. So, if it is for two channel audio, I would look at it as an opportunity to upgrade if the rest of your system is of a higher quality. 

My home theater has two B&W 800 series subs that were made about 20 years ago. I have had them each re-taped and upgraded. For home theater they work great... I got rid of the two I had in my audio system as it got better. 

My main purpose is home theater and the earthquake has been enjoyable for action movies for sure.