I love my 'June Tailor Shape Cut Plus' and has it definitely helped with accuracy. However, I've found that pressing the fabric before cutting is necessary. There always seems to be 'rumple' in every piece of fabric I buy. Even the good stuff! It's just not worth taking a short cut, and not press....
I'm still deciding if I'm a fan of the grip dots. They're great for the actual cutting, but a hindrance when sliding a ruler atop the fabric and getting to the measurement I need.
My cutting is a little odd, but I have seen one other person on YouTube cut like me.... PHEW!
There is such a HUGE learning curve in all of this. Trying to find what works 'just right for you' takes time and patience.
And a few off-cuts! I hope you find your way.
I'm still learning to find mine, and will for a long, long time. And that's okay.