I just want to chime in to say I'm loving the new exploration mechanics so far. I find it's actually faster than the old method when I jump into a new system. Just do the "Honk" while getting into a good fuel scooping position, throttle to idle, then bring up the FSS.
It immediately tells me how many objects there are, and the frequency spectrum display tells me what type. Just icy bodies? I'll move on. An Earth-like world? I'll scan it (which is MUCH faster than the old method of having to fly to it).
Overall it feels like there's more to do, it's easier to do, and it's quicker. It's a win-win-win for me.
Unfortunately it's not quicker if you are used to jumping in, throttle to full, honking whilst manoeuvring to get optimal scooping AND exiting the gravity/heat well of the star as quickly as possible, hitting jump as soon as you're at 60% heat and then flipping to the system map to see what's there whilst the countdown timer is active.
The FSS requires you to throttle down (and it takes you down to 30Km/s whilst you're looking at it) and you can't use it during the timer countdown (it says that you have to be in supercruise).
This adds between 5 and 10 seconds to the jump time per system. On a 700 jump traverse of the galaxy that adds approximately one to two hours to the trip.
I've timed it.