The abundance of functionally identical elements with different design (disk guides, fasteners, fan filters, chassis feet, etc.) make us suspect that Fractal Design is still trying different solutions in practice in search of the best one. The current products are but a testing ground for the Perfect System Case of the future.
Choosing among what we’re offered right now, we'd prefer the Arc. If it had the same side panels as the Define XL and if its USB connectors were farther apart, it would be almost perfect in its midrange category. Well, the Arc is actually one of the best offers in its price range even in its current, slightly imperfect, form.
Being the most affordable of the four, the Core 3000 is of course simpler than the Arc, yet is as good as the latter in terms of ventilation (except for HDDs, yet it's HDD results are not too bad, either). Some assembly-related inconveniences and the lack of USB 3.0 (even optionally) are made up for by its modest price.
The more expensive Define series products leave fewer positive impressions. They do look good and are very quiet, but that’s about all of their advantages. The numerous manufacturing defects of our Define R3 (hopefully, other samples are free from them) and the design flaws of the Define XL, combined with their mediocre ventilation, can hardly make them interesting for ordinary users who are not bent on making their computers absolutely silent.
As a final remark to this review, we can note the irony of these system cases, each of which can accommodate a large number of hard disks, coming to our test lab right at the time when there is a sharp rise in HDD prices!