It largely depends on how much portability you need.
Since you can connect your PC directly to the router using Ethernet, the LAN side should not pose any issues.
For the WAN side, the Puli AX includes removable external cellular and Wi-Fi antennas, which can offer better performance in weak-signal environments. You also have the flexibility to upgrade to third-party higher-gain antennas or use magnetic antennas with extension cables to position antennas near a window/outside for improved reception.
The Mudi 7 provides the highest portability, but its built-in antennas may not perform as strongly as those on the Puli AX. If you are confident that the areas you visit have reliable coverage, this may not be a concern.
Using a Slate 7 paired with a budget-friendly 5G phone is also common. However, this setup requires external power, such as a portable power bank. In addition, lower-cost 5G phones may have limited band support or weaker signal performance compared to the Mudi 7 or Puli AX.