Considering these are to be used as a router, what are you planning on powering it off of? I can't see much use where you'd put this unit behind a poe switch aside from maybe blocking a problematic device (in a corporate setting to meet security requirements). If it's for a small switch scenario, you'd get the performance out of a (slightly) cheaper dedicated switch.
The lan side of the router could be POE powered, connecting to an internal POE switch.
Heck, the POE switch could be on the WAN sorry just using VLAN tagging.
Or just a POE injector anywhere.
I'm not objecting to the barrel plug, it works its serviceable it's reliable. I just have a lot of equipment, and therefore a lot of extra gear, with POE injection so it would be convenient and clean up my rack