It can get slow [hdd grinding when moving stuff around] when using security, so I use balanced most of the time and is responsive. But, my experience is my experience, as each machine is different, so, see for yourself. As for your second question, you are free to do so. If my memory serves me right, ASC has anti malware solution inside the package, so make sure there are no conflicts [both eating each other out, exclusion of folders of respective programs perhaps?]. Try it out and see, it should be compatible. this is what I run every day http://s33.postimg.org/4dw7li5tb/tray.jpg http://s33.postimg.org/4dw7li5tb/tray.jpg from left to right: O&O Defrag Pro, Qihoo 360 TS, connection indicator, volume control, notifications suppressed, language selector and time & date BUT, on standby, I have HitmanPro, MBAM, Emsisoft Emergency Kit, Norton Power Eraser, Comodo Cleaning Essentials, and some stuff from GeGeek Toolkit laying there somewhere, collecting dust On Sunday, during lunch, I launch qihoo full scan and these scanners just to be sure Each week That is what/how I do, but you are free to devise your own strategy. Just pick something you are most comfortable with and does not impair your ablity to use your computer.