Hey @har8549 - sorry for the trouble you've been experience. I'm in the Mid-South and have had great service - have travelled to the West Coast & the South and have not had any issues personally.
If you are having trouble you can request for a SIM reset/reprovision through Visible Chat on the website which may be worth a try.
There is also a plan to add additional nodes this year to decrease of network latency which would improve the service for those that are in Western or Southern parts of the States.
Finally you could also try a different SIM card in your phone from a different carrier to rule out that it wasn't the phone itself playing into the problem...
I am in a northwest suburb of Los Angeles. The Visible signal here outdoors is OK. Web pages load up pretty fast. You can even watch 480p or 720p YouTube videos.
(I use Visible mostly on an Macbook laptop tethered to an iPhone 7 Plus inside my van.)
However, I don't know about Visible's signal strength indoors. When the pandemic is over, I will be spending most of my time inside a local library, like pre-pandemic. One poster's experience with poor indoor coverage kind of unnerves me. I plan on upgrading to iPhone 13, when it comes out. Fingers crossed that the signal will be good enough INSIDE that library!