Those programs are handy, I personally use Prime 95, but real world game/application testing will always tell the full story. Even tho some systems run these burn in test programs for hours/days on end with no crashes, sometimes when you run a game (e.g dirt 3/farcry 3) it will crash and burn within 10 minutes and you are like what!?!? I didn't change anything?!
I look at it this way:
1. Does it run without major frame rate drops? (yes)
2. Is it stable
all the time? (yes)
3. Is it really worth me burning something up for an extra 10 frames per second? (No)
I used to be an overclock junkie, learnt the hard way, was overclocking my i7-2700k from 3.9ghz @ 4.5ghz voltage increase from 1.245 to 1.350, DDR-3 1600mhz @ 1687 also voltage increased, video card increased from 1084mhz to 1250mhz, then one day the motherboard fried, would only recognise the ram at 1333mhz. Luckily only fried the board and not the CPU/RAM/Video card, no warning either, just pfaff! there was plenty of cooling too, no overheating. Sometimes you can slightly fry a pc internally and it will give you hell randomly for the rest of its operational life. It may not crash/freeze for 2 weeks, then one day when you have spent 5 hours on a major project that's when it will sting you.
I still take risks with my video card when a new version of 3dmark comes out, cant help myself, like a young car hoon, gotta have a burn once in a while! But I understand if it burns up or just stops working that's the risk taken, all just to try and beat that 3dmark score
These days I do a mild PCI express clock from 100mhz to 102.6mhz which gives me 4ghz instead of 3.9ghz on the cpu, this board is too expensive to fry (ASUS P8Z77-V PRO), a slight increase on the PCI express bus (under 3 mhz). It can also add stability for stubborn systems having trouble running @ stock speed without voltage increases.