Any Sunfire HRS owners out there?

I recently purchased a b-stock HRS-12 sub for HT, and I am happy with its performance. I have also been browsing this site looking for other sunfire HRS and have yet to see a single one for sale. Is it because it is so good owners do not generally sell, or because there just aren't many out there?
I am curious. I would also like to get feedback on this sub.

Thanks.