Well, I went and bit the bullet last night and ordered the Stripology square up ruler. $52.99 for a 12" square ruler. Now that hurts. Thank you lindachipper for bringing the Matilda rotary mat to my attention. I hadn't known about it. I like the 1//4" markings on it. Wish they had put a 60 degree angle on it. I am torn between it and the Martilli.
Also, thank you RhondaK for your suggestion on trying a 60 mm cutter for better control. I thought the smaller the blade the better the control, but I'm a novice. I will get one and try it. And yes I do use grips under all of my rulers now. It's more my hand not behaving.