Given the router is only capable of delivering the bandwidth your ISP is providing via HW acceleration, you've effectively outgrown it. It's one of the reasons I'm presently looking to move my router to a x86 desktop platform (e.g., pfSense, Untangle).
This will be an increasing problem as ISPs offer even more bandwidth (>Gigabit) in the months and years to come. HW acceleration is essentially just a hack to keep the current crop of consumer-grade routers and their relatively weak components relevant. But it tends to break things, QoS being one of them.
In short, I don't see any consumer-grade routers being up to the task unless manufacturers step up to the plate and vastly improve the specs on their routers. More likely, they will continue down the current path, trying to squeeze out performance improvements at the cost of feature loss to save money. And hoping most ppl won't notice and decide to look elsewhere.