Long story short (can provide more details as needed) but I've switched ISP's twice in the past ~week. I started with Suddenlink 200Mbps cable, then had Centurylink 100Mbps fiber, and now I'm back to Suddenlink with 400Mbps cable (admittedly limited by old 8 channel SB6141 modem).
While I had CL, I got a very steady ~100 Mbps download speed. I wound up cancelling the CL service though because it tended to drop out a lot during the day.
Now since going back to SL, I get very different test results here at TMN specifically. Of course I get a solid ~250Mbps at speedtest.ne
