I recently replaced a bunch of halogen GU10 base bulbs with LED versions in rooms in which we most often have lights on - living room and kitchen.
I ran a calculation in excel based on 4-hours of average daily use and our mid-peak energy rate and a cost of $25/bulb. (Philips, with warranty). Break even was about 3 years. In past, when the lights were $50+/bulb, they didn't break even over a reasonable time period. Coincidentally, it was the MMM blob post that prompted me to run the numbers.
FWIW, I don't see the point in using LED globe lamps; for non-directional use, fluorescent is far, far cheaper and since the bulbs are warrantied, there's no reason to spend extra on LED on the grounds of "longevity". For directional lights, LED is the only way to go.