The Corsair Frame 4000D clocks in at $95, which is fine, but considering that you can get the RS with three non-ARGB units or even the RS ARGB with its illuminated fans for just $5 or $15 more, it feels like Corsair missed an opportunity to make the basic Frame 4000D a cheaper way to get into the Corsair ecosystem. In comparison, the RS120 ARGB triple-pack has an MSRP of $54.99. While those are not priced well, that means that the Frame 4000D could have clocked in at $5-10 less and still retained the bundle benefit of going for the "biggest" SKU variant in the line-up. That said, naturally, this does not consider Corsairs remaining product stack, with the MSRP of the 3000D at $84.99, which actually includes two SP120 fans. So there is a bit of tweaking Corsair could do while still retaining the integrity of the pricing structure overall.

While you could find other mid-tower, BTF capable cases with 3–4 fans for less than the bare Frame 4000D, it is a good thing that the RS or RS ARGB offers more bang for the buck, as the chassis can be considered to be a great case that manages to do everything really well. The Infinirail is functional, even if it is a simpler implementation than what we have seen in the 9000D. The 3D front panel is quite the prominent unique selling point visually and the case's modularity has plenty of potential, if Corsair manages to back it up with a solid ecosystem quickly. This needs to be in the form of a set of physical SKU parts as well as a solid library of files to allow users to design/3D print their own components.

The biggest issue we see actually ends up being the quality of some of the metal components that just don't reflect the premium price that the case demands. While that isn't a functional problem, it is just quite obvious at the moment and a tangible, stark contrast to what one would expect. Besides that, one could argue that the word "modular" is a bit loaded these days, but the Frame 4000D manages to offer much more than other cases in the market with that same marketing approach.

Ultimately, while the basic Corsair Frame 4000D may feel a little more costly, it does provide some nice engineering and design details. Those who are missing that price/performance, will find that in the RS or RS ARGB versions. We would love to give the case the Editor's Choice award, but the core premise of modularity and the robust parts ecosystem is not (yet) present to really make it a no-brainer to pay extra for the modularity the Frame 4000D provides. So, until that is the case, the case is still a rock solid recommendation thanks to the great functionality and engineering.