I have both the pinking blade and the wave blade.
I have had no problem. I don't use them a lot, but they have worked fine when needed.
Agree ... important to keep all straight and at right angles when cutting.
One thing to note ... when cutting against a ruler, be really careful to not damage the blade.
It's very easy to slide up next to the ruler with it, and nick the blade against the ruler.
It can happen with a regular blade, but IMHO, easier done with one of these specialty blades.