Southampton port is easy to find as it's so well sign-posted. Our experience was flawless and quick. We arrived at the gate and were directed to the correct area. We drove right up to the doors and there was someone to open our car doors and unload our luggage. We walked straight into the terminal and there was no line to get to the priority boarding desk at all. Check-in was quick and efficient and very friendly (everything is done with a smile!), and we walked straight through what I assume was security and straight onboard. The whole process was uncomplicated and took maybe 10 minutes at most.
Although it was a lovely day, this would have been a perfect port for rain as everything was entirely covered and warm.
Again, easy and uncomplicated disembarkation. Walked straight off the boat and although it is all uncovered, it was very quick. Straight off the boat, quick flick of our passports and into like a warehouse with all our luggage in rows. Then straight back out the doors and there's a taxi rank and a car park right in front of you. Although you don't really need either if you're staying in Hamburg as it's all so close together you can walk to most places.