I've got a SIP 150 Mig set, its old, and i got it in used condition from an old chap who comes to work, its been a little belter. I don't do vast amounts with it, its just a handy thing to have, but it is gentle enough to do thin panel work, the heaviest ive done was at work to do repair work on a Land Rover chassis when the big mig set packed up. Fairly versatile for a little 'un, so in my opinion i can't knock SIP stuff at all