Untangle multi-wan modules are subscription based, but they are the most brain dead easy multi-wan on the shelf, and the best part about them IMHO is the fact that you the admin define via your own test what is "down". So there's no ambiguity, it does exactly what you say it's going to do.
Now, when you toss in VRRP and do a clustered Untangle configuration, things can get more than a bit confusing because VRRP needs an IP per interface per device, and then it also needs a shared address. It can get VERY fiddly and it wastes IP addresses. The trade however is once again SPEED. The fail over is almost instant.
As for the QoS, Untangle's QoS rack module is called Bandwidth Control. What isn't so apparent is that Bandwidth Control is a rack app, not a service app. Because it's a rack app you have have multiple QoS rule sets, with different configurations and use the policy manager to match traffic and move things around.
So you could for example, deprioritize youtube traffic for some users, while prioritizing it for others. I've not found another QoS implementation this flexible, allowing you to have priority access for power users regardless of what system they're on keyed to their AD logon. Or perhaps granting special consideration to the machine in the conference room.