Zach, you are indeed correct for 2/3 models of 2004, unfortunately I grabbed the one to compare which has a CPU frequency of 1.2 GHz ( Amazon Annapurna Labs Alpine v2 CPU with 4x 64-bit ARMv8-A Cortex-A57 cores. While this CPU is running at 1.2 GHz, the router can be 3x as fast than the previous generation CCR’s) vice the other two with same processor have a CPU speed of 1.700 GHz (this CCR also features the Annapurna Labs Alpine v2 CPU with 4x 64-bit ARMv8-A Cortex-A57 cores running at 1,7GHz.)
The difference being for 25 IP Filter rules at 512 byte chunks
RB5009 --> 3096 Mbps RAM- 1gig 4 cores ( No rules fast path - 9552 Mbps )
2004 1.2 CPU --> 2768 Mbps RAM- 4gigs 4 cores, ( No rules fast path -207300 Mbps )
2004 1.7 CPU --> 4565 Mbps RAM- 4gigs 4 cores ( No rules fast path - 27644 Mbps )
IPSEC
rb5009 - 489 Mbps
2004 1.2 - 831 Mbps
2004 1.7 - 831 Mbps
RB5009 -- $219
2004 1.2 -- $465
2004 1.7 -- $465 or $595
So clearly for 3x 1gig WANS, the RB5009 or two of the 2004 models fit the bill.
On a cost basis the RB5009 fits the tighter budget.
If one had a high priority on IPSEC throughput, then the 2004 becomes more interesting. ( come on MT put wireguard speeds on your tables!!! )
One should note that for heavy loading, the 2004 with its additional RAM and connection processing power would stand up better.
If one added one more WAN at 1gig each (4) only the 2004 1.7 CPU would be appropriate.
If one added one more WAN at 1gig each (5) none would be appropriate and the 2116 would be the preferred solution.
If one had two wans of 2.5 gigs, none would be appropriate and the 2116 would be the preferred solution.
2116 $995 --> 25 ip filter rules -- 16,088 Mbps, fast path - 37,377, CPU 16 cores, 2 Ghz speed, 16gig RAM
by my experience. 750gr3 is 880mhz x2 ht to 4 and given it 1gbps without any rules just simple route the cpu can go uptp 80% still see speeds to 600Mbps only.
i took one i3 6thgen thats a 4 core 3.7 GHz processor and slapped normal realtek 1g lancards into it
wan1 1Gbps wan2 500Gbls wan3 300Gbps
when i try with only 1G its shoots to 1.2Gsometimes and comes to 800G 900G and preforming good
at a day 300 people are using through it

ahd stable ( its on proxmox chr)
let me get my hands on a managed router with 1000Mbps 8 ports and 10g sfp upllink. vlan it to a 12th gen i5 with proxmox chr and vlan ,that would be cost effective
the only downside of vlan is that i will have to make a way for managed router to send and make a file in the router about actual port speed and then script the CHr to show in logs what is the connection state of the wans