As I recall. most of 301 was 4 lane. Maybe some 6 at the very utmost North end.
The problem, and what helps the various 'speed enforcers', is that there are many small towns with lots of stoplights along the way. And, the speed limit changes constantly between 35-45-55 mph. By no means is it a straight shot, and that is what adds to the speeding problems in that stretch.
Getting on 75 is pretty easy, once you get there.
If getting stuck on I-4 is a big concern, I would say jump on 10 across to 75 then come down that way. It's longer than the 301 route, but by the time you factor in all the start/stops and 35 mph zones on 301, the time will be similar. My in-laws take that route when heading to Sarasota, as they dislike the I-4 traffic. (Note: they don't do the 301 either, due to the constant starts/stops at all the lights.)