I have a White serger and owned a Pfaff serger before this one. I have never had any issues with it and threading is easy though not easy as Baby Lock. The tension has also never been a problem and have sewn light weight fabric to fleece with it. I think its a 200ATS, and may no longer be available. Definitely reasonably priced.
Read reviews and if possible, try one out in the store. What someone else likes, another doesn't. Buy the one you like.