The verdict

CPU
Dell OptiPlex 5070 Micro has 1.5x the CPU throughput (8,026 vs 5,357 PassMark).
Plex
Topton N150 4-LAN transcodes more 4K HDR streams (~5 vs ~3).
Idle power
Topton N150 4-LAN idles lower (8W vs 9W) - cheaper to run 24/7.
Networking
Topton N150 4-LAN has more NICs (4 vs 1) - better for a firewall or VLAN trunk.
RAM ceiling
Dell OptiPlex 5070 Micro takes more RAM (64GB vs 32GB).

Which wins for each job

Job Dell OptiPlex 5070 Micro Topton N150 4-LAN
Plex / Jellyfin ~3 streams ~5 streams win
Frigate NVR ~4 cameras ~4 cameras
Proxmox / VMs 8,026 PassMark win 5,357 PassMark
Firewall / router 1 NICs 4 NICs win
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 Dell OptiPlex 5070 Micro Topton N150 4-LAN
Price (list) $120 $117
CPU Intel Core i5-9500T Intel Processor N150
Cores / threads 6 4
PassMark 8,026 5,357
iGPU Intel UHD 630 Intel UHD (24 EU)
NICs 1 4
NIC model Intel I219-V Intel I226-V
RAM max (GB) 64 32
M.2 free 0 1
PCIe slot none none
Idle (W) 9 8
TDP (W) 35 6