Using newer compiler versions and the optimizer gives gas optimizations and additional safety checks for free!
The advantages of versions 0.8.* over <0.8.0 are:
- Safemath by default from
0.8.0(can be more gas efficient than some library based safemath). - Low level inliner from
0.8.2, leads to cheaper runtime gas. Especially relevant when the contract has small functions. For example, OpenZeppelin libraries typically have a lot of small helper functions and if they are not inlined, they cost an additional 20 to 40 gas because of 2 extra jump instructions and additional stack operations needed for function calls. - Optimizer improvements in packed structs: Before
0.8.3, storing packed structs, in some cases used an additional storage read operation. After [EIP-