I've had two lines with Visible Mobile for quite some time and have been well satisfied. "On-device" bandwidth never seems to get into double digits but it's more than sufficient for what I use my phones for.
Recently they sent me a notice saying that I could maintain my $25 pricing and still move to their new network that includes roaming, lower ping times, and other improvements. I also hoped that I would see much higher data speeds.
I got my new SIMs and activated them but didn't notice much of a difference in speed.
I thought it was odd that speed tests would often shoot up to a high number and then quickly settle down to something in the 5 Mbps range.
Since my phones allow me to pick specific LTE bands using the MTK Engineering app, I used Network Signal Info Pro to help me watch what was happening during speed tests.
Invariably it starts out on the fastest band (13, for instance) but as soon as the bandwidth goes above 5, or so, it switches to another band. If the speed is still too high then it switches me again until I get "managed" into a lowish single-digit range.
I've seen YouTube videos where Visible Mobile customers get 200Mbps+ but in my rural area that just doesn't happen.
Anyway, using MTK Engineering, I disable all but the fastest LTE band and-- voila!-- a consistent 20Mbps+.
Occasionally there will be days when the fastest band is 4, 5, or 66 (2 doesn't work in my area) so I'll change it to that band. Usually it's 13 for us, though.
So, if you've got a phone that lets you control the LTE bands (like the ZTE Blade A7 Prime or 10 Prime) then you can probably increase your bandwidth by managing it yourself instead of letting Visible do it.