That is really going to be a matter of opinion since both have their advantages and disadvantages. The primary advantages of the ATX supply is their durability and warranty that they have. They supply all of the voltages that the hub or Zeus requires without the need of adding those regulators to the device. The disadvantages are that the big ones can get a bit expensive and they tend to have a lot of connections that are not used by our equipment and seem to just get in the way. You also can't adjust the 12V output which can lead to issues with some of the poorly designed nodes out there.
The primary advantages to many of the 12V only supplies is cost and the ability to adjust their 12V output. I have seen many 40A 12V supplies selling for around $20.00 which is less than many ATX supplies with similar power outputs. They also don't have any wires coming out of them so there are no extra cables to get in the way. The disadvantages are that they don't have many wires coming out of them which includes the power cord. IOW, you need to supply your own. You also will need to add the extra components to the hubs and Zeus to supply them with the 5V and 3.3V that they also need. With many of these, quality is not the #1 concern and they have no warranty to speak of but for that price, what do you really expect. You also need to use some heavy gauge wire between the supply and the device, especially is there is any distance between them or you can expect some substantial voltage drops.