I have not sailed from Port Canaveral, only Galveston, but I can share a bit about the process.
We thought the Galveston boarding process was very quick and smooth. For two adults and a five year old who have never cruised before, we made it from shuttle pulling into the parking lot to enjoying the ship in about 40 minutes. (That included our own luggage confusion at first, a lengthy bathroom stop for all involved, and actually standing in line for the picture.) From what I understand, it's a very typical boarding process: security, inspection of the alcohol you are carrying onboard, going back to check in (we encountered no line and no waiting), and then going up the escalators to board (again, only a line for pictures.) The cruise terminal employees and Disney CMs were all incredibly polite and helpful.
We also flew into Houston Hobby. I wanted to test different transportation options, so we did Uber XL out to Galveston (totally fine) and Galveston Express on the way back (really liked a lot.) If you like to have scheduled transportation, I highly recommend Galveston Express. If you prefer something like Uber, be aware that there is often surge pricing when the cruise ships debark - especially if there are two ships in port.
We did a pre-cruise stay at Hilton Galveston Island, and that was great. Their pool was nice (although we didn't use it because it was cold in December) and you could walk to restaurants for dinner (we at at Rainforest Cafe, which was a dream of DD5 after seeing the one at
Disneyland.) Also, my husband walked to Wal-Mart on our embarkation morning to grab a couple essentials and forgotten items. So, the location was great. I am a Gold HHonors member, so we also received complimentary buffet breakfast with our room - this is a nice perk for HHonors members. We used the Hilton/Hotel Galvez shuttle for transportation to the port, which you need to sign up for at the valet stand the evening before. Our PAT was 12:30 but I wanted to get there at 12:00, so we took the 11:30 shuttle. It was perfect.