Prefer to just use my Internet connection to be honest, and test it if things seem to be wrong. YMMV and I know some people are 'avid' speed testers.
EDIT: Just as an aside I'm pretty sure the TBB tester is fine at 1Gb. It's on a 10Gb network.
Edited by Ignitionnet (Mon 14-Aug-17 22:32:17)