I have a Brother I bought some 20 years ago right before I stop working for Wal Mart and I use it when I am making my clothes or taking in clothes for my grandaughter and it still works like a dream. I have never had an ounce of trouble with it at all.
It is a 3/4 thread overlock and the only thing that I wish it had is the auto adjust for the thickness of fabrics. Most of the new ones do have that feature.
I have found for lower cost machines they operate and last extremely well and am just waiting for my husband to find a job (he lost his 6 months ago) so I can buy an embroidery machine from Brother.