I can't imagine doing without a serger for clothing construction. There are just too many threads for me to want to use it for quilting, but there is nothing better for making knit clothing. I made so many knit tshirts and sweatshirts for my children! I also made a lot of slacks, or at least most of the construction was done on the serger.
Those who say a serger is hard to thread need more practice. Some definitely are harder to thread than others, but mostly it is a matter of lots of practice. The sequence of threading is absolutely critical, or at least they have been on the sergers I have owned. In the serger classes at my LQS, they make the new owners thread the machines from scratch 8-10 times in the class! I think that is the only way to really get good at it.
Pam