That is an understatement. The manuals are terrible.
Did you know you can run the balancers in layer4 mode which will deliver higher performance? Not possible through the vShield web interface (plugin), has to be done through an API call.
Did you know that if you enable cookie persistence against a layer4 farm it reverts back to layer7?
It is always up to the customer to write their own manuals I think.
My advice, enable Layer4 balancing and use IP_HASH as the algorithm, then you'll have persistence without requiring cookie insertion.