The verdict

CPU
GMKtec NucBox M5 has 1.8x the CPU throughput (19,000 vs 10,450 PassMark).
Plex
CWWK X86-P6 transcodes more 4K HDR streams (~5 vs ~3).
Idle power
GMKtec NucBox M5 idles lower (8W vs 12W) - cheaper to run 24/7.
Networking
CWWK X86-P6 has more NICs (2 vs 1) - better for a firewall or VLAN trunk.
RAM ceiling
GMKtec NucBox M5 takes more RAM (64GB vs 48GB).

Which wins for each job

Job CWWK X86-P6 GMKtec NucBox M5
Plex / Jellyfin ~5 streams win ~3 streams
Frigate NVR ~4 cameras win add a detector
Proxmox / VMs 10,450 PassMark 19,000 PassMark win
Firewall / router 2 NICs win 1 NICs
Local AI / LLM no slot no slot

Approximate - capacity estimates from curated specs, the same logic as the recommender. Verify against your exact setup. Prices move; check the retailer.

Full specs

Spec CWWK X86-P6 GMKtec NucBox M5
Price (list) $320 $329
CPU Intel Core 3 N355 AMD Ryzen 7 5800U
Cores / threads 8 8
PassMark 10,450 19,000
iGPU Intel UHD (32 EU) Vega 8
NICs 2 1
NIC model Intel I226-V Realtek RTL8125
RAM max (GB) 48 64
M.2 free 4 2
PCIe slot none none
Idle (W) 12 8
TDP (W) 15 25