I did the round trip about three weeks ago. There was significant construction between Jacksonville and Daytona. The good news is that things are a little better on the route through Jacksonville which has been under construction for a couple years, but just after you get past there, there are lane closures much of the way to I-4. On the way down I was travelling through at about mid-day on a Saturday. Volume was heavy with the lane closures, but I was not significantly slowed.
On the way back was passing through in late afternoon on a weekday. No big problems until I actually got to Jacksonville. There were a series of SIX separate accidents/disabled vehicles. Not sure if this was unrelated or perhaps caused by confusion of the construction and debris in the road. I'd say the traffic caused by this added about 45 minutes to my trip through the area.
Luckily or unluckily I've been conditioned to the DC area traffic so none of this really phased me too much and I wouldn't have taken a longer alternate route to avoid it, but if you really can't stand delays you might consider it.
