Good to know about having slack. I was letting the machine pull it. But, even in the image above (which was only 6 inches deep), it still got off. I do run the vinyl back and forth before cutting to make sure it's not drifting. If it does drift, it's usually because I don't have it fed in square, so I'll reset and then test run until it feeds straight. I have the blade dialed in. It's doesn't cut deep enough to cut the back, but it cuts deep enough to cut the vinyl. Any lighter and it will not cut the vinyl.
Budget - I'm still small time and trying to grow, that's why $x,xxx is possibly doable, but $xx,xxx+ is out of my range just yet. I'm new to cutters, so I'm honestly not even sure what an "entry level (good)" cutter would start at. Yeah, this machine is entry level.... but the good is still questionable - although it could be operator error.