Last year I decided to replace all the halogens in my office with LED's, but was surprised at how much they vary in light strength, quality, and area of illumination depending on manufacturer.
These Philips ones give great light - the cool white is very cold though - and cover just about a wide enough beam.
The estimated lifespan is 5 years for most of these, and when you feel the difference in heat output you will understand why.
Bear in mind that halogen bulbs can be used in mini ovens, all that heat is bound to degrade old style bulbs.
The tiny amount of heat from the LEDs means for places like offices you can have a massive energy saving.
They aren't cheap, but this new generation of higher equivalent wattage means you can replace old halogens and recoup the cost of the LEDs.