The double-packed box more than withstood the rigors of UPS. There was no damage to the case.

The case was more than I expected. The pictures (here and elsewhere) don't do it justice. It is roomy, well built, beefy (not light!) and well finished. The dust filters are not magnetic, but snap in; they should be something that you are careful with.

The case isn't a deep monster, but has enough room for a good build. I'm using SAS drives and while the drive connectors extend into the "motherboard area" it hasn't been a problem. That said - I have four 6TB drives. Depending on the number of drives you have and the amount of drive cooling you want, YMMV. I haven't had a chance to resilver an array so I don't know what internal temperatures would be like. But, so far, so good. It will probably take me a couple of weeks to become aquanited with the nuances of the case.

The "handles" on the case are sturdy and more than support the weight of the case. I haven't installed rails as my rack hasn't been built yet. The case handles remind me a bit of the old APC UPS units (that kind of sturdy).

The case connectors were long enough for my build, but I could see issues with others - depending on motherboard, components and cable routing. In my case everything went together well.

There have been complaints about not being able to remove the drive trays or moving parts around but that doesn't seem to be a problem - it may take a few seconds to figure out what to unscrew but it can be done. I don't know if any parts of the clone cases will fit, but I'd be game to try.

Overall a nice case. Yeah it was expensive, but I think it was worth it. AND it was in stock.
The only nit to pick is the use of the small screws (use a magnetic tipped screwdriver!).

I have enough parts to build a second server. If I had the same requirements, I wouldn't hesitate to use the same case.

*** UPDATE ***
I had to replace hard drives as my sas drive went to the bit dumpster in the sky. I purchased some ironwolf sata drives and found that i can only use two mounting screws to secure the drives. I don't think it is a fault ot teh case, but having deeper hard drive bays would allow for secure mounting of hard drives. And a curse on Seagate for deciding to omit screw holes. So if secure hard drives are your thing... you might want to take that into consideration...

All in all, this is a perfectly functional 4u chassis, with a couple small issues. For the purposes of this review, if I say "bottom" I mean if this were oriented in a traditional tower configuration.
1) Its not as deep as I was thinking. Wasn't a problem for me, but if you try and fit a full sized PCIe card and then add drives to the bottom(if it weren't rack mounted) cage, you're going to have a bad time.
2) The bottom drive cage technically fits a 120mm fan, but the hole in the cage is only about 80mm sized.
3) There is no hardware to mount a fan to the top drive cage, I had to jerry rig it myself. They don't advertise that you can put one here, but I think its a missed opportunity.
4) The tiny screw, oh my god the tiny screws. A) there is twice as many of them as really needed. B) I think they probably could have just used 1 larger one, rather then 2 tiny ones in most cases.
5) The little plastic window that shows the front panel LED, fell off almost immediately. No, I wasn't rough with it, I promise.

Using this for our security camera server and it is great. Sturdy, roomy, good fan layout (though we added our own to fill it up), and perfect packing! It arrived in great condition due to their quality shipping/packing material.

I was searching for a new chassis for my home server and kept striking out with several big name manufacturers. One key was case depth, and most competitors were between 20-25" deep. I don't have the space for that. So I started researching based on dimensions alone. The RM400, at less than 18", had a clear advantage. Two things struck me on first looking at this case: the symmetry, and the included locking bezel (with filter). It's obvious that this case was designed with both form and function in mind, and it isn't lost on users. Upon further examination, I grew increasingly more excited about the small details: the front windows to show LEDs even when the bezel is closed, case design, the chassis intrusion switch. Then you dig deeper: In addition to eight 3.5" drive slots and three 5.25" bays, though not advertised, there are spaces for three 2.5" SSD drives (or 2 SSD and 1 Slim Optical drive - yes, Slim Optical).
I do have one warning: because this bay is shallow - a major selling point for space-conscious buyers - it only has about 7.25" of space from the edge of a standard ATX motherboard to the front bezel. In other words, a Hot-Swap bay like the Supermicro M35T, which is 7.7" (plus fan housing), obstructs the motherboard and doesn't work. Likewise, the Silverstone RL-FS305B hot-swap is listed at 7.8" (though I don't have one, so not sure if that counts fan or not - YMMV). This can be overcome by installing a Mini-ITX or Flex-ATX motherboard. It can also be resolved by installing a standard optical drive, which is 6.7".
All in all, the RM-400 is a spectacular case. If you choose components you want and design them around this case, it will make an exceptional system.

For the most part this is a fine case. All the holes and screws line up nicely. The built in air filters were the main reason I chose this case. Both included case fans are pwm controlled and plenty quiet.

It is 4 inches shorter in depth than the case it replaced, and this made for some nearly impossible fitment (pictured). You can NOT fit a gtx 1650 super while 3.5 drives are mounted in the left drive shelf where the drive fan is - one star deducted. I had to put all my HDDs on the middle shelf where there is no fan. One more inch of total depth would really free up this design a lot.

The sides of the case are tapped and threaded for drawer rails, and sure, they sell drawer rails, but I already had rack slides. No normal sae or metric screws on earth fit these threads, so I had to tap them to 10-32. It was sad, but not hard.

All 3 Drive shelves are easy to remove, but the sata ports on the MB were dangerously close to them, and two sata cable connectors died while trying to make things fit.

These shelves are each isolated by large rubber grommets and it seemed like a really nice touch, probably helps with vibration some.

Front panel buttons and USB connectors are very good quality.

Paint finish is excellent.

This would be a 100% perfect case if it were one inch deeper and used normal screws on the sides.