They all seem to be much more GPU-focused? i.e. completely different product segment?
And mostly (with a couple of exceptions) significantly larger than something named "MicroServer".
They are perfect for data crunching as well as GPU related purposes.
For IO: My 8 year old one lets me saturate SATA at 500megabyte per second. With SAS which it also supports it's supposedly 3000megabyte per second, bit I have never tried it.
For memory: ECC
For processing: Dual Xeon CPU config
For storage: Nice storage pods.
For admin: Out of band ILO like functionality, although I've never tried it