US 17 is about 40 miles shorter and <10 minutes faster, according to Google Maps, but for that small difference I would double-check using the times you will actually be driving.
The US 17 route is rural; I 75 takes you just East of downtown Tampa, but then mostly rural because it runs East of the coastal cities. I think you're less likely to have major drama on US 17, but frankly I have never used that route.