Well it isn't easy on the system, but since I have 1258 RAM that's not a big issue. I use shareware version because I've done some translations for them so I got lifetime license
As far as for the interference, over time I set it up like I want. And when you use some tool for quite some time you get used to it. But for sure, I wouldn't recommend it to any nervous person, because sometimes really gets in the way of peaceful work.