They can be efficiently implemented in logic families like CMOS and TTL.
OR-AND-invert gates implement the inverted product of sums.
A 2-1-OAI gate realizes the function with the truth table shown below.
A 2-2-OAI gate realizes the function with the truth table shown below.
[1] One possibility of implementing an XOR gate is by using a 2-2-OAI-gate with non-inverted and inverted inputs.