For mine, I'd rather have more than 'enough' than too little. A machine that is under-powered or has bottlenecks will struggle under load, whereas a machine with more than ample will cruise along and not skip a beat... and video editing/conversion, etc, does chew a bit of RAM.
My philosophy entirely....headroom. There are people out there that claim PSUs over 600 watt are a waste of time...bla...bla...bla...
God knows what they say about my "Corsair ASX 1200I Platinum Certified 1200w Modular PSU" [probably ...."wanker"] but my system is all fan...no water...and I only ever hear fans at boot....[part of their initializing process] ....rest of the time they are idle. It's the first time I've managed to make a QUIET computer...and considering its size...and the need thus for it to be on the desk immediately behind the monitor...sideways ...it's both 'in your face' and 'in your ear' so silence is golden.
Re ram... load up a couple of VMs and you'll soon prefer to have had more...than less...
Yeah, but then you have to wonder, those who say that kind of thing, just how 'low-end' their machines are... and how much envy is involved. Thing is, I have a fairly high-end machine with plenty of grunt, but given I do like to keep up with the latest and greatest PC tech, I must admit that I get a little green with envy when I see or read about others with bigger, better , faster, more modern machines than mine.
My Intel i7 4790K rig has a 1200w Platiinum PSU... AND 32 gigs of RAM. A waste of time, power and money to some, but I do have [now] 15 x 2 - 3 TB HDDS installed in it, several of which are/can be accessed at the same time, so why wouldn't I want to ensure I have more than ample power to run all the installed hardware... without as much as the slightest flicker?
Besides, when your graphics card recommends a minimum 700w PSU, a 1200w doesn't seem all that drastic, what with all those HDDS, a 250 gig M2, a 512 gig regular SSD, a ROG MARS Dual GTX760 graphics card and a Creative Soundblaster Z... not to mention the 9 internal fans and other nick-knacks/add-ins. Yup, the more hardware you install, the greater the power required to run it efficiently. Currently, however, my Intel machine is undergoing some minor internal work/changes and thus is temporarily out of commission... hence, I am using my AMD FX8350 rig in the Thermaltake case until the Intel's back on line.
As for the tower on the desk top "behind the monitor... sideways", I simply don't have that kind of spare space on my desk top, hence my two main towers reside beside the desk on a stand I made... cos they're way too fechen big to fit in the desk slot usually reserved for PC towers. The Coolermaster Cosmos II is almost as tall as my desk when on the ground, so no way it is going fit in the [even smaller] pigeonhole in the desk. In fact, given the extra floor space this setup takes, I may even remodel the desk to accommodate the towers and peripherals more efficiently..... all I need now is the motivation after suffering 3 weeks of worse than usual vertigo.