Hah! You are making me want to replace the cables in a new boat, Bruce.
To answer your question directly, the throttles are not bad, but not very smooth either. Takes significant effort to operate, and it can be tricky if you are trying to accelerate very smoothly. Don't get me wrong, it is not like you have to use two hands to move those, but I would NOT call them smooth.
I may need to look into adjusting the friction screws! I think I did it in my 190, but it did not completely fix the problem. It was still not smooth.
My understanding is E-throttles eliminate those issues completely.
However, when I was shopping, I was not able to get strait (and consistent) answers about some of their features. Such as: will those work with no aux power in the boat? And I think the reverse limiter is crazy. So, I like the idea, but I just didn't have the nerve.
(As an aside: What actually helped most with my 190, at the end, was the ECU reflash - I found a program that made the throttles operate smoother than silk. Which makes me believe it is a combination of cable adjustment and throttle body programming that smooth throttle operation makes. )