First of all I just want to say, anyone considering AG, do it. It isn't that hard and makes way better beer IMHO.
Anyway.... Saturday I did 4 AG batches in a single day (3 tier MoreBeer propane system). Previously I had done 2 or 3 in a day and 4 seemed doable.... In total it took about 11 hours from start to finish (including equipment setup, milling grain, sanitizing equipment and all cleanup) and all went smooth. Last batch was a Pliny the Elder clone with 90 minute boil so a 60 min boil could have shaved some time off.
Getting a rhythm with the batches worked out well. With 30 minutes left in the boil I would mash in the next batch, this worked out almost perfect for me to finish the boil, cool (through CFC) and clean up boil kettle for next batch to be ready to Vorlouf and sparge.
For the last batch (Pliny) I was concerned about amount of Pellet hops being an issue (I generally just whirlpool and have no screen on outlet valve of brew kettle) so I used a Muslin bag (large 12 x 24). That was pretty much useless..... Wort flowed through well and hop utilization was decent I think, but when done, about 2/3 of hops were on the outside of the bag in the kettle anyway. Whirlpool was only so-so effective and some hops were sucked through CFC (but no clogging), I figure no biggie since this gets dry hopped anyway. So from now on I will only whirlpool, seems to go much better.
If anyone has any questions, I can try to answer. To me doing multiple batches makes sense as the additional setup and prep is minimal and for someone like me, my opportunity for brew days are limited.