English Votes and English Laws (EVEL): What is the best response?

A few months before the General Election this question is more debated than ever. The participants discussed alternative recommendations of solutions to the EVEL question. What are the advantages and flaws of the different options and what conclusions can be drawn from the experiences of other countries, such as Germany? A constitutional reform as an answer to the EVEL question would be the most fundamental reform of the structure of the Union since its creation.