Which mode is most frequent?
Load equalization is used when Cells having similar configurations (Bandwidth/Coverage/xTxR/etc).
Load offset is used when main layer (Higer BW) is to be offloaded after a certain threshold toward low BW Cell.
Better to use both PRB and User based on Connected mode (Load Equalization or load offset, that is depending on ur Cell configurations).
Using connected mode always help to reduce relatime load bcz UEs live and using resources while shifting IDLE UEs will be having less impact.
Load balancing based to IDLE mode help to prevent frequent HO ping pong and GAP measurements.
I mostly observed PRB Usage Based Connected Mode Load Equalization.