I'm currently behind a Linux router with basically nothing but firewall rules configured; I still get an A on that test (meaningful?). I guess this sort of thing is just the default nowadays?
What router? what ISP? What link technology? What bandwidth? A pointer to your dslreports result? There are plenty of small ISPs that have adopted this stuff... and a few router makers.
I am always happy to hear of a bloat free connection.
You're one of the lucky ones with an ISP with properly configured buffers.
A+ is the goal on that test though, which basically means no extra latency under load.