I live in Sarasota, 100+ miles away on the west coast, and with no clouds, it appears as a bright light and smoke trail.
With binoculars I can see the 2 boosters separate from the shuttle.
I am in Savannah, GA and we get a great view of the launch as the shuttle appears to climb out of the ocean. We’re about 230 miles from the Cape. For night launches, we can see the initial firing of the engines and then, about 2 minutes later, the craft pops up over the horizon. We see it all the way to MECO (Main Engine Cut Off.
I have seen shuttle launches from as far away as St. George South Carolina. I was coming home from college, driving on I-95 and pulled over to watch it clear some trees on the other side of a field. Thats 310+ straight miles from the Cape with not a good horizon at all.