Neat idea, but it might get kind of confusing, especially in the cases where there are multiple solutions.
I agree that it is rewarding to know you've helped. But I still find it encouraging (in any job or endeavor) to look at a growing number of successes, and the successes are more "tangible" when they have that visible checkmark beside them. Also, it is beneficial to show that problems are solved to save the time of our wonderful sages who browse through the posts (I presume) looking for those who need help.
That is a good point. Hadn't thought of that; of course, I haven't been around on the forums long enough to be affected by that.
Anyway, I'm accepting your response, @Geo, as the solution to my question