No expert knowledge here, but from my research when I was rebuilding my 5.3
Accumulator is cheap insurance on a expensive build. Since mine was basic with cam and springs I didn't find it necessary.
But if funds and space on buggy was avaliable I would have got one
I looked into it when I was doing my 5.3 swap they seem like a very good cheap insurance if you have a good bit of money tied up in your motor also pan selection is a important thing to look at as well I have the kevko 5 quart F body pan and haven't seen a need for the accumulator as of yet but I also only have $400 in my entire motor so it was hard to justify spending $400 for an accumulator to save it
Pros are never a dry start on motor, oil pressure at all angles, depending on what size you buy that many more quarts of oil to circulate in motor.
Cons. Only one I can think of is money spent on one but it's one of those items you can keep and not have to ever replace no matter motor or rig it's in.
Not saying they are a bad idea at all but I've never used an accumulator and never had a problem. I've run the Kevko pan on every LS engine I've had without issue. Id say they certainly aren't necessary but definitely not a bad idea.
I just have mine plumbed directly with no switch. I have the dipstick marked for the 3 extra quarts. It saved my engine after I knocked a hole in my oil pan and didn't notice it on Crackhead at GMP.