I had 2 in a row - so 6 years in total
I loved it - no side effects, got a period every 4 or 5 months and no spotting in between.
By the end of the second one (so 5 years after infest used it) I started getting migraines once a month but they continued the same after I got it out, so I don't think there was a link.
For the first month I got really bad pimples on my face, so I asked the doc for a medicated face wash and it cleared in a week and was never a problem again.
Seems it's the only contraception that truly works well for me