Go with the rosewell if you buy a premade rack, or are handy with some metal scraps, a hacksaw and a rivet gun.... Only basic tools/skills needed.
In my eyes its extremely optimal. You can route air from the front to the back (or vice versa) which makes airflow across the cards very controllable; and feeding a filtered air source, or funneling hot air out to a ventilation point.... Most open racks and such are efficient; but they get dirty; and quickly depending on circumstances.
I literally took a slide in mesh screen from an old pc case, and pushed it flat up against the fans in front. Mainly to catch the large dust and debris that causes the biggest and fastest airflow problems.
There is tons of room in this case for the larger GPU's.... You can easily fit the EVGA GTX 1080/70 ACX3.0 style ones in there; they are the cards that are super large, overbuilt power phases, etc. I love the case. Its robust, plenty of room, good mounting room, you could even fit a second PSU if you wanted to squeeze.
The upgraded fans are a must with over 2x GPU; you need to move the air through the system to get enough convection cooling plain and simple. They are in an enclosed space. The OEM fans are low speed and don't move enough air for that amount of heat. 2X gpu stresses the capability of the original cooling fans. A 960 SSC and a 980 to be exact; I wouldn't put another GPU without swapping out the fans.
Its nice having a self contained unit. I just have the back of it pointed towards the outward air, and the inlet towards the fresh air source. My personal one is in a room that has a thermostatically controlled ceiling fan to keep temps in the room down, so that's one scenario anyways.
Better airflow through the miner makes a hashrate difference of 8-10%. No joke. Once I swapped for a free flowing mesh screen, in the same exact position/conditions, I get higher hashrates. All cards on stock settings mind you. Trying to keep it as static of a test as possible. I bet if I upgraded the fans, it would be fine with the old filter and grill... but it would clog VERY quickly and heat right back up.