The main difference between using Convex and Stakedao for liquid staking CRV is the rewards and APRs associated with each platform. Convex rewards holders with a fixed APR of 5% for staking CRV, while Stakedao offers variable APRs depending on the amount of CRV staked. With Stakedao, users can also take advantage of their Liquid Lockers feature, which allows them to stake their CRV and receive rewards in VESDT tokens, which can be used to purchase additional CRV tokens. This provides an additional layer of liquidity and flexibility to the staking process. Ultimately, the choice of which platform to use for liquid staking CRV will depend on the individual user's goals and preferences.