I can only speak of my experience with Charter Oak. Actually, I bought my machine and the CNC kit from Industrial Hobbies when Aaron owned it. After using it for several years, I am still impressed with the speed and accuracy of this mill. I just ran 9 identical parts yesterday. I just picked a place on each part and measured it. The maximum deviation from design was .0015, and I am in need of tramming and adjusting the entire mill. Earlier, after tramming the mill, I was getting .0004 average deviation.

Like you, I did a lot of research on mills before buying. The thing that attracted me to the IH mill was large working envelope, servo drive motors and the ability to use full flood coolant. I have no regrets on my purchase. At the time I bought it, it was the most bang for my buck.

In terms of technical support, I have called Charter Oak with support questions and they did not hesitate to help me.