I had been sewing for years before I had a serger in my arsenal. To be honest, when I received it, I thought it was superfluous (I wasn't sewing with knit back then as much) but nice to have. Fast forward a few years and I can't imagine my life without it. It is my workhorse, and we are best friends.
Those first few months, however, were a struggle. Uneven edges. Loopers off the fabric. And most troublesome of all, curves.