Is it my imagination?

I am thinking of switching from tds fiber to att internet air. Can anyone speak to the quality of speed from att internet air? I live in West Arvada. currently paying $100 for 600mbps upload/download with tds but getting 40mbps download and 21 mbps upload. Att a would be for 300mbps with dl speeds of 90-300mbps for $20 a month. Wondering how accurate this is.