Summary: How many people actually use their machine to their full - very few I'd guess. Now, of course, if you're programming for NASA and trying to use it in space rockets or some such, I'm not going to say it will work flawlessly. But for day to day tasks, you'll have no issues. Multi-tasking - no problem. Playing games - no problem. Surfing, emailing, writing documents, etc - all no problem.
Summary: Coming from an i7-920 to an i5-4670, my computer SCREAMS. Load times for games are cut in half at least. It's really a great processor and I think I found the sweet spot for higher end gaming before diminished returns.