I am an electrical engineer so I know the problem you speak of very well - you can believe what I told you. I have done research on impedance mismatches and how they affect traveling waves and what the optimal resistace/inductance and transconductance/capacitance ratios have to be for distortionless transfer. The issue is that you are taking "rules of thumb" as gospel. When people say the impedance ratio should be 10x, they mean AT LEAST 10x. This means that 200x is MUCH BETTER than 10x. If you had 10x, it would not be as good as what you have now.
In truth though, it depends on the impedance curves and not the values quoted on the brochure. I have seen systems with an impedance ratio of 1x and it be fine because the curves didn't hit each other. The fact of the matter is that the 10x rule is just to be sure that the impedance curves are far enough apart to not hit each other. The farther apart the better - and 200x just makes it all the more impossible for the curves to interfere.
Secondly, a second system for comparison is nice but how do you know that one is the best? Well, you don't! There is nothing perfect and there is no absolute. All you can do is experiment until you are happy.
Your system is just fine. Enjoy the music! take care, Arthur
