Well, I did a batch sparge of a Janet's Brown on Ale on Sunday, and a Big American BW on Tuesday. Both were 10 gallon batches.
I think Batch sparging can save time, but around 15 minutes for a 10 gallon batch of a reasonable gravity beer - the heating of the wort is the critical path. On Sunday most everything went to script, and it was about 4.5 hours, and I left the system in place once cleaned as I was brewing again soon. My previous fly sparge record was 4.5 hour for a 1.038 bitter, but there was less to heat up and so on, and that day included clean up and put away.
The BW was more involved and the day was longer. Had a few problems with hitting temps, so had to add heat and so on. A long boil off to hit the target, but it was not a bad day, and the beer should be good. The 70 qt. cooler let me mash 42 lbs, so I hit a little higher gravity than with the keggle with false bottom mash tun.
Having done both, I can see why people like one or the other. It comes down to what you are comfortable with, your equipment, and what works.
Guys in the club make good beer on many systems, so it is the brewer/brewster and how they make the system work for them.