3 more points. The Superbe is a better ship, but not necessarily when you factor in point costs. I did rank the Soleil Royal as the best French gunship. Looking at that, Superbe should probably be #3.
Which one is better just depends on the points you have available. If you can include Superbe without cutting too many corners, the speed is likely to be worth it. However, the Soleil has a better ability and the Superbe can’t do much against ships with L-immunity like the Jarvis. Soleil is a better budget gunship and one of the best cheap 5 masters, while the Superbe has better range between the speed and all L-range guns. Both are great so you can’t really go wrong here.