From my perspective:
Glassing off a ball head.....sucks!
Shooting off a panning head.....sucks!
My solution has been to glass with a panning head (Sirui VA-5) mounted to a full length center column (RRS Ascend 14L). Combined with carrying a RRS Anvil 30 (with bolt, washer and allen wrench) on my pack’s waist belt (Marsupial Gear 'small zippered pouch' ....works great).
When a shooting situation presents itself, generally, you’ll have time and opportunity to pull the ‘glassing’ center column/panning head out of the legs and attach the Anvil 30, using the bolt and washer. This can be done in under a minute.
If you don’t have time to do this...you’re prolly looking at a closer range shot and could use another, hastier, option for supporting the rifle. An example would be....throwing an Armageddon Gear Pint Sized Game Changer (filled with Git-Lite fill) over the top of your panning head and then you'd still be able to shoot off your tripod.
An example of all of this coming together, played out on this years' moose hunt. We glassed from a ridge, using the panning head, for 5 days before we found a bull we wanted to kill. Before the stalk began.....I swapped the center column for the Anvil 30. During the stalk, which lasted about an hour, we relocated/kept tabs on the bull using a pair of 12x binos mounted to the Anvil 30. Because my spotting scope plates and binocular adapters are Arca-Swiss compatible....it's easy to go back and forth with different head types. Once we got within range of the bull...the rifle was direct connected to the tripod.
We were in waist -to- shoulder height brush, the entire stalk, once we left the ridge top.
If I have to choose between carrying the extra weight of an Anvil 30 or a bipod.....there's no doubt it'll be the Anvil 30.
I would've hated glassing all day, for 5 days straight, with the Anvil 30 and wouldn't have wanted to shoot off the Sirui pan head when given an opportunity at a bull. Honestly, swapping back and forth between heads is no big deal.
View attachment 348398