For me, this looks like the platonic ideal of a subwoofer. It is basically flawless. It's the perfect balance of performance, aesthetics, price, and manageability. The performance is all-around excellent, as the review shows. Yeah, there are a handful of less expensive subs that you could get more output from, but they are a sacrifice in every other respect: they don't look nearly as nice, and they are usually a lot larger and heavier. Here we come into manageability, I wouldn't want a sub that I can't move by myself. Placement makes a big difference in the bass sound, and I need a sub that I can try in different areas of the room without having to call a friend, so goodbye to all the subs that weigh 150+ lbs. By the way, from some google searches, it seems the FW 18.0 is 130 lbs., but that isn't in the review or product page, however that would be a bit of useful information to be included.
There are few subs that look as gorgeous as this one. I would say that high end KEF 18" subs looks as good but that thing is 5X the price. That is seriously the only one I can think of that is a match for the aesthetics. Using a grill on the 18.0 is a crime though, that really ruins it. It reminds me of that awful bumper they had to put on the North American version of the Lamborghini Countach which completely ruins its curves. For a reference, the European Countach:
and the US Countach:
Ugh!
Another thing is I think a single driver per cabinet sub is the best solution; less heat, less weight, and fewer moving parts for greater reliability. I would prefer this, and I would also take the 18.0 over the 18.3, yeah those PRs will get you more deep bass around a certain point, but only by sacrificing SPL everywhere else, and also making the sub a lot larger, heavier, more expensive, and less visually appealing, and probably adding a good chunk of group delay to its performance as well.
As for the cost of the 18.0, yeah it is expensive, but not unattainably expensive like a JL Gotham G213, Paradigm Sub 2 or the aforementioned KEF sub. And that cost can be mitigated by getting the passive version which is only $2k. You could get two passive 18.0s and a couple of iNuke 6000s for $5k, that would be a killer setup. I agree with the review, for the caliber of cabinetry involved, this sub is a bargain. If I were on the market for some subs today at this price range, the 18.0 would be at the top of my list, but I am all set up for subs for the time being, and my next upgrade would have to be my speakers at this point.