So, after a long exploration trip to Colonia with the Fast Scan DSS, I switched to a Long Range DSS and heading toward, once more, to Sagittarius A* (maybe, Thargoids will be kind to me if I do not mess with them...). I have to say that I definitely enjoy more the Long Range one. Being able to scan very far objects is way better to me that the slight faster Fast Scan. The difference in time it's not so good, and for close objects it's almost unnoticeable. This is quite remarkable for scan that far away lonely gas giant or companion star...
When you are approaching a big HMCW and your scanner start scanning at 540Ls (which mean that in normal circumstances, for the same planet, it will start at 195Ls), it's an HUGE advantage. It's very time saving, as you do not need/have to approximate if your following objects it's on a very different vector. So, it give me more freedom in trace an elegant path across the system. It also frees me to those frequent deceleration/acceleration sequence, as I can stay more on 60-70% SC speed.
Thanks to all for the help. Fly smart, fly safe!
CMDR Spadino
EDIT - Beeing able to scan an M star from 16000Ls it's very funny!