That's a bit challenging. I know I'm not here to speak personally, but you did ask a personal question. The answer is that I've done that lots of times, because I'm always curious.
I had a recent experience. I'm on a 150 mbps package. In the past I have exceeded the 150, but I was dealing with my own ISP. I had one of their reps in my office right here. When I said, “Let's go to one of these speed test sites”, we did that. It then depended on which server we connected to. One of them said I was getting 130 and another one said I was getting 80.
I don't know what an average consumer is supposed to do with that. In particular, if I have an “up to 150”, my service provider has met its commitment. They've given me up to 150, whether it's 80 or 130. That, I think, is the problem with the “up to” advertising.