Conclusion: Lost in Translation
Let me first come clean and say the BitFenix Shinobi XL is by no means a bad enclosure. Performance is at least reasonably competitive, and while it doesn't achieve Corsair levels of ease of assembly, it's nowhere near as difficult as some of the more elaborate Lian Li and SilverStone cases can be. People looking for a good water-cooling enclosure are definitely going to want to check it out, as the case is capable of supporting a cumulative 1080x120mm of radiators. In many ways this is what Corsair was gunning for with the Vengeance C70, but I think BitFenix has done a better job here.
The problem is that if you're not planning on doing any serious water-cooling, the Shinobi XL loses a lot of its luster. Acoustically it's among the worst of the cases we've tested; it's noisy even under idle conditions, and that noise doesn't come with commensurate thermal performance. As a big fan of the original Shinobi, I feel like the XL causes the brand to lose a little bit of its luster. This is now basically BitFenix's premium offering (alongside their Colossus), but their generally excellent performance south of $100 is nowhere to be found here.
On a more subjective note, I also feel like the Shinobi XL isn't as aesthetically appealing as its smaller sibling. The design language just doesn't scale up quite as well, and in many ways I don't feel like the aesthetics and design are competitive with other cases in this price class.
I'd say if you're looking for a good case to do a custom water-cooled build inside, the Shinobi XL is probably worth considering. Users planning on doing air-cooling or using smaller closed loop coolers need not apply, though; the much less expensive Antec Eleven Hundred is going to be both quieter and cooler.