I haven't worked with anything at that scale, but the little bit that I was SuperMicro adjacent I was always unimpressed by the "fit and finish" of the entire experience, as compared to Dell and HP. (Having said that, the entire x86 commodity server experience is shitty anyway. I had a brief time, early in my career, when I did work with DEC Alpha machines. Man, they had their shit together. Stuff was expensive as sin, but stuff worked together and worked well. Build quality was tank-like.)