What is the difference between latches and flip-flops based designs

Latches are level sensitive whether flip-flops are edge sensitive. So, latch based design and flop based design is which latch permits time borrowing that a tradition flop does not. It makes latch based design more capable. But at the similar time, latch based design is more complex and has more issues within min timing (races). Its STA along with time borrowing into deep pipelining can be rather complicated.