This wasn’t even a customized machine though - it was off the (Amazon) shelf, just really high-end for the time. Afaik they didn’t offer any variants with more ram or storage. Just Intel or amd, with nVidia or amd. You got more storage with the Intel version, and the second slot as NVMe, but that was it.
The asus was likely a better built machine, but as being one-or-the-other, specs trumped niceties.