The argument to not implement an upload limit is the ability to abuse the feature, therefore i have figured out a way which can't be abused
the idea is you have 1 slider in your options panel, the slider will limit your upload speed but will also limit your download speed at the same time
so if you set the limit to 80% you will also have 80% of your download speed left, so only people who really need to limit their upload will use it otherwise your download will be reduced for no reason
I don't know if this feature is practically possible (i'm not a dc++ programmer) but I would really like it because i have a download speed of 180 kb/s but when someones download something from me, the speed drops to 1 a 5kb/s so at this time it's not possible for me to share
hope you like the idea, sorry if it was posted before