There are no differences in the Orbs staking mechanism between Ethereum and Polygon. Orbs Delegators have the ability to choose between staking on Ethereum and staking on Polygon, based on their own personal preferences and considerations.
However, each network has its own characteristics that can appeal to different Delegators:
Ethereum is the native chain for the ORBS ERC20 token. As such, ORBS tokens on Ethereum are compatible with any other Ethereum wallet or protocols or services using ERC20 standard.
Polygon, being a scalable L2 solution on top of Ethereum, offers significantly lower gas fees when interacting with the Orbs staking contracts. This enables certain special features such as staking rewards auto-compounding which is only available for Polygon staking.
Note that each network requires its own token for transaction fees: ETH for Ethereum and MATIC for Polygon.