I will probably cop some flack for this, but I'm very happy to have individual "taps" for each wing tank.
I don't need to fly out of balance on purpose.
Can run an individual tank down to a certain known level and isolate it there, knowing 100% there will be no transfer between tanks and that exact level will remain.
I can leave more fuel in the right tank to help keep the aircraft balanced and wings level in flight, one up.
Both tanks isolated while parked makes someone stealing the fuel harder. Isolated taps and locked doors. (They need to syphon and not just drain tanks)
If parked across a slight incline, fuel does not cross transfer and drain out the breather.
When taking off with both tanks full, I can run each for 10 mins, taking the top off each.
I have also run a tank empty in flight (controlled situation) and fuel did NOT begin to flow to the engine when the "full" tank tap was opened.
Only when the empty tank tap was closed.
Meaning the mechanical fuel pump kept trying to pull from the empty tank until it was shut off.
(This seems to be the reason for this crash but they had no tap to shut off on the empty tank to get fuel flowing from the full tank.
The horror of knowing you have fuel in one tank but can't get it to the engine!)
For me, after closing the empty tank tap it took about 2 or 3 seconds for the engine to resume to normal operation.
Note. The engine never stopped running, it lost power and "spluttered".
As I knew exactly what was happening, my corrective measures were instant.
Quite possibly in a "real" situation the engine would have stopped as the shock of the situstion and fault finding would have taken time.