none of these problems people are having are issues with the RUU.
bad battery life, apps not showing up, phone getting hot... it's all things that individuals are doing, in addition to upgrading the RUU.
many people have confirmed that this update makes the phone much better, and i can attest to that. if you're having issues, re-evaluate your individual circumstances - apps you've installed, the way you installed the RUU (did you have other processes running on your PC while you were installing? while you were downloading the file?), whether you have wakelocks, whether you cleared your data, faulty hardware, etc.
if you download the RUU properly, and install it properly - unless your hardware is just messed up, or you do something that i mentioned above - your phone WILL be better off after the update.