Methyl cycle length

[devil]

In most of the posts I'm reading people are running methyls for 3- 4 weeks. Based upon my experience I'm having a hard time believing that this is enough time to really do anything other than glycogen load and retain some water. I would think you would need to run them at least six weeks to actually gain some muscle tissue. I understand that methyls are very hard on the body. But is an extra two weeks really going to be that damaging?

I know that people claim to be maintaining gains on these short cycles. I'm curious to hear feedback from some people who have done short cycles and then taken some significant time off from these products.