After talking to the third Xfinity tech, she sent a "partition" or something like that which increased the speed. The first tech claimed he did the same thing but it didn't work. Here's the interesting thing. If I run the first test site I'm getting about 550 mbps. When I run the second site, there is an IPv4 and a IPv6 test. When I run the IPv4 I get over 800 mbps. When I run the IPv6 test I'm getting 750, still great. I don't get why there is such a large discrepancy between the two tests, which are both from Xfinity's website. Also, if I set my modem at IPv4 instead of automatic would that maintain the 800+ mbps?