If you've never seen one, watching it from Orlando will be amazing.
As you get closer, it gets better of course and weather plays less of a role. I've seen them from St. Petersburg, Gainesville, Orlando, New Symerna, HWY 50, HWY 520, Cocoa Beach, Titusville and once with a ticket from the cape.
Bring lots of sunscreen, and be flexible in your plans - scheduled doesn't mean it's going to happen that day - there's no such thing as making an appointment to watch a launch. Delays can be seconds, minutes, hours, days and weeks.
In summary:
1. So long as you see it, you'll be amazed.
2. Timing is more important than location, you'll spend all day getting in and out of the "perfect viewing location" whether it launches or scrubs.
3. The best viewing locations require a ticket - but you still can't plan a vacation around a launch unless you're retired.