It depends on the time of day. 429 is a very fast road, not a lot of traffic, but 192 can be a nightmare if you hit it just right (took us an hour and a half to go 4 miles the other day around 10:30am). I would still take the turnpike to I-4 until the Disney entrance from 429 opens, but again it all depends on time of day whether or not one way is faster than the other way... Heading home though it would be a lot faster to go out to 192 and get on 429 from there as the traffic in that direction (going away from Disney) is not usually bad on 192.