I have a clarke 160en running on flux core wire, and I have done a lot of welding with it, and other than when I have 'made' it weld things that I havent been able to clean up properly.
Such as as galvanised gates, sheep hurdles and such like I have never doubted its weld quality and the ability for them to stay welded, you have been told a lot of bull.
On clean well prepared joints it does a great job, every time there is a comparison of hobby machines the clarkes always come out high in the rankings, and price v performance then they are a winner.
It annoys me when people try to scare people into buying something totally unrequired, stick with the clarke.