Tune the broadband test to get actual download and upload speeds, as with technologies like 'PowerBoost' (which increases the speed dramatically only for the first 20 megabytes or so) will greatly inflate true download speeds.
If you only use third-party testing suites like Ookla, you won't be getting the true download speed and/or capacity which users actually experience. Other than simple buffering, what good is reporting that I have a 2.0 MBps connection, when after a few seconds of downloading, the stream gets trickled down to a mere 700 KBps?
It's difficult to test, as you would probably need a very large file to download (and then again upload). But it's crucial if you want valid numbers.