I'm completely in love with my pencils!
I went ahead and ordered a pink and got it yesterday, I love, love, love, love, love it and I'm glad I switched over from the pens. As much as I loved using them, getting them to work lately really has been difficult and after the nightmare I had troubleshooting my machine, I didn't need anything else to stress me out, so I got the Sewline's.
Peckish, it sounds like the leads are old, mine worked like a charm right out of the package. I'd definitely replace the leads and toss the old ones out.
I'll be getting the black next, I'm just nervous about it because I know that sometimes, black can be particularly difficult to remove. I wanted blue but I can't find it on Amazon, but that's okay, I'm fine with black. I'm having no issues with mine coming out at all, I keep forgetting that I'm using pencils instead of pens and when I go over the marks with my iron (I use a lot of steam), the marks come out even after I've ironed.