What's the difference between 2-cycle and 4-cycle gas hedge trimmers?

Reviewers note that 2-cycle engines require pre-mixed gas and oil but tend to be lighter and simpler, while 4-cycle engines (like the SENIX 4QL) run on straight gas with no mixing. Across the reviewers we read, the no-mix convenience is the headline appeal of 4-cycle, but it generally comes with added weight and a lower owner rating in the data here.