I actually was thinking about that as well on a somewhat related issue. As we gain active users it becomes significantly easier to obtain a full wheel, but after the wheel becomes full it is no longer possible (from the post) to accurately see how valued (or circled) it continues to be. I was wondering if you might be open to considering weighting the circle system as votes accumulate. Or rather if anyone thought this might be a good idea. For example, I think that the first vote a post or comment gets should always yield a circle added to the comment. But what if after that it took, say, 2 additional people to click the post before it earned another circle, or something? I don't think this is an imminent issue but I thought it was interesting. I had also considered how the speed of the site is changing.
It's hard to say what a good system is. Still, the majority of posts and comments get 0 or 1 share or click-of-approval, respectively. Then, out of the blue, something gets 20 shares, or who knows how many confidence clicks. Maybe throttling is the way to go: spoke 1 and 2 take one vote, three and four take two each, and so on. Not sure, but it's worth thinking about.
Another idea, perhaps when the 8 spokes complete the wheel in a comment, additional shares would come up as a tiny (+#) for how many upwheels it gets, like a super-superscript of the wheel. So a 12-upwheeled comment would have the fully-spoked circle with a tiny +4 beside it. Just a thought.
Yeah, it's being considered. I think it's more of an issue with comments than posts, currently. I like that I can see every user that has shared a post. But yeah, it's getting to point where we need to examine these things.