Videotron Giga Speeds

Can those with the Videotron GIGA plan confirm what the FASTEST SPEED is that they've achieved (whether on a single device, or across multiple devices)? I've had techs come to 'fix' the speeds several times now -- the last time, I was told that it was likely a firmware issue with the Videotron modem, and that while the line can go the full 1gbps (930mbps in reality), the modem can't seem to deliver more than ~500mbps max. They told me they would contact me when there was a fix, but it's been several weeks now and I haven't heard anything, so not sure what to believe at this point.