Sounds like OP is leaning a certain direction and has been in contact with REL.
Here’s my $0.02 with dual 98s:
Preaching to the choir here, but as a reminder for future readers interested in the down-firing Classic series: don’t ignore your flooring material. I’m talking tile vs deep pile carpet vs suspended wood flooring. For example, deep pile could make the Classic sound muffled compared to tile.
With that said, and compared to previous subs I’ve had and listed below, I’ve found the Classics to be the best sounding in my current space. They truly extend my main speakers while contributing to a deeper soundstage and ambiance - perhaps from the radiation pattern and nature of a down-firing sub?
Another strong point is their integration which is so incredibly natural and easy to find, whereas previous subs took months. Beyond the impact of placement, my uneducated suspicion is that the Neutrik Speakon connection aids with this subs ability to integrate so flawlessly.
Additional considerations/critique: they seem a little “rounder,” less tactile pressure, and don’t include a variable phase which should be standard on all subwoofers. Yet they still sound better than the my previous subwoofers that are technically better:
HSU ULS-15, Rythmik F12G, and customized Rythmik subwoofer via Omega Speaker Systems.