For me, it depends on what I am doing. I always use temporary spray when I use washaway stabilizers. I'll use an iron-on washaway when something is very stretchy or thin.
Caroline, I have never seen iron on stabilizer where I live in S. Africa, so have never used it.
I use iron on tear away all the time. I love it. Sometimes I do not fuse it (vinyl) and it still works fine.
I use iron-on stabilizer when required (have never had an issue with gummy needles). After embroidery, the stabilizer can be reheated for easier release and trimming. I truly dislike cut-away and avoid it like the plague.
I use fusible tear away stabilizer for T-Shirts and onesies... It helps stabilize the stretch of the knit and helps alleviate puckering from the stretching of the knit with the density of the design. After embroidering, I remove the fusible tear away and then use a fusible knit backing to cover the embroidery (like Cloud) which prevents the embroidery from irritating the skin while adding the support that T-Shirts need without adding any bulk and it cannot be seen from the right side of the shirts.
Only use the iron on once in a great while with really wimpy fabric or tricky situation. But, I do have some, just in case.
I like the no iron, for some reason the iron on either makes my needle sticky or becomes hard to deal with.
I've just actually used the iron on one making my runners. I've not found it to be any better or not than my usual tear away, other than it's a bit firmer in one direction. Good luck and I look forward to reading what others think. Love Chris
P.S. Caroline, we had lots of rain yesterday, not enough to make any difference down here in Newcastle NSW, but further up north some places got over 100mls in a day!!!!
Great Rainfall ,here in the Shoalhaven we only had 10 mls.Hopefully we might get some more Today love Ursula