You don't see the benefits because, with all due respect, you don't really understand what's going on. Free ram is wasted ram; it's there to be used to *increase* performance and by default, left to its own devices, that's exactly what 7.1 and all previous versions of IOS do.
Where it falls apart is where people like you insist that manually emptying ram is somehow helpful; it isn't. If the system needs more ram for the current task it will get it, if it doesn't then all you are doing by closing down apps is increasing the likelihood that it will have to reopen those same apps itself the next time. And that's not even figuring in the wasted screentime and processing of you going through the list and pointlessly flicking away every five minutes.
"Heavy and prolonged use" is the life of most iPhones, certainly mine. It does not require any such tinkering and I do not consider it buggy. Yours apparently is constantly tinkered with and seems "buggy" to you - I wonder which came first?