Awesome feature, I have been reluctant to trying 1.9 out due to the previous ignoring of rate limits, but that has been fixed and I decided to try it. Setting my upload to unlimited (before I limited it to 50) it varies from my max upload (100-160KB/s) to anywhere lower, giving enough bandwidth to not bog down my network. Long story short, after running it all day at unlimited I have not noticed it running at all (in terms of browsing speed) and neither have the others on my network. "Install" the new version like normal, then take the installer exe and put it in the uTorrent install directory. Rename the old .exe to something like "uTorrent.exe.bak" just incase you wish to go back to the old version. Now rename the new exe (the one you just put into the uTorrent directory) to uTorrent.exe......it should work perfectly fine, thats how I managed to install it over 1.8.3 and it is working fine ATM.