Yes, as much as I like the Fast.com speed test, I don't think its the most accurate. I can get inflated numbers when I do tests with it, yet when I look on the interface on the router I'm seeing the 'real' numbers. Use something like speedtest.net or dslreports speedtest as these will give more 'accurate' numbers.
If you want to know a queue is working correctly, max it out and watch it go red when it actually is kicking in. If it isn't going red then its not being maxxed.
I much prefer to use queue tree with PCQ, which is a little more complicated (as you have to mangle the traffic correctly) but I find it works really well and can do things like assign all the bandwidth if only one person is using it, then scale it down to guarantee someone else some bandwidth, much more dynamic and it can split bandwidth equally between hosts.