I couldn't find much about the Hilton Southampton posted on FT so I thought I'd provide some input!
The location is just off the M3/A27 motorway, though you have to double back on the roundabout to get to it. The location isn't that great for Southampton itself as it's about 5 miles into town. Car parking at the hotel is £3 per night.
The hotel is on the rim of a punchbowl with the motorway around the rim, so the tip is to get a room on a lower floor. There are 5 floors in total. Mr GoodTimes and I always ask for a quiet room, but they initially gave us a room on the 4th floor right at the end, next to the motorway! We eventually got a room on the 2nd floor which was much quieter. Wine, water and chocs were provided on both nights of our paid stay
The reception is on the 3rd floor, btw. The gym/pool was on the 2nd floor. The gym was quite good despite being cramped with too much cardiovascular equipment. The restaurant was on the 3rd floor, which turned out to be very pleasant.