I'm not sure I see the point of any of these stacks as they add more card readers when you just got one. I've got my CalDigit TS3+ dock from my MBP, if I get a Studio I could pair that with it for the extra ports. Only thing some of these stackers have that could potentially be nice is the SSD drive slot, but truthfully I don't want to make the Studio taller.
The original poster seemed to be after additional USB-A ports and the design of these seem to be made for the Mini which lacked the card readers. I have seen some card reader tests (I think Constant Geekery on YT) that show an external card reader being able to read or write to cards quicker than the one on the Mac Studio, but not sure if that warrants the duplicate reader.
The OWC miniStack STX that I ordered actually only provides three additional powered Thunderbolt ports (which does not help the OP), along with an internal (to the hub) M.2 slot and 3.5" drive bay. I have several single bus powered Thunderbolt drive enclosures along with three Thunderbolt quad drive enclosures. The extra powered Thunderbolt ports in addition to the four on the Mac Studio will come in handy for me.
I haven't set my Mac Studio up yet (tomorrow I will finally be able to do it), but I have read other posts that indicate a powered Thunderbolt hub might be needed to supply power to multiple bus powered thunderbolt drives on the Mac Studio (a different thread here suggests this), but I am not sure if that is true.
As for going vertical or horizontal with the expansion hubs, I prefer taller due to decreasing desk space with all of the enclosures 😂
Can anyone tell me if the round bases on the Studio, and the Mini, are the same diameter? Thanks in advance.
I should have answered your actual question directly instead of going off on a tangent. Yes the Mini and the Mac Studio are almost the exact same footprint. The round bases might not be exactly the same size, but any of the hubs you are looking at that has the Mini sitting on top of, should also easily work with the Mac Studio. You can actually see how close the Mini, Mac Studio and G4 Cube are in this video (@4 minutes in is where the comparison starts):