I've been searching the forum for advice on undercabinet lighting. I have ruled out the Xenon because of heat. My electrician is recommending LED light strips (which he has never used). I don't have much room for transformers and would like to see a sleek light fixture - not very bulky. I want to illumninate my soapstone counter and backsplash (material for that isn't determined yet). Some have used linear lighting - what kind of light is that? Any thoughts or suggestions would be so helpful!

"I thought that a larger transformer would better regulate against line spikes and voltage fluctuations" Maybe, but not always. Keep in mind that low voltage often requires higher current (though LEDs are not as bad as incandescent bubs). Wiring that runs concealed inside walls get smacked by the whole electric code unless the voltage and current are both low (power limited circuits) Wiring on the underside of cabinets at low voltage gets a lot of breaks. Even more if the circuit is also low power (power limited circuits, think like your doorbell or thermostat). Even with LEDs you may not get all tat much light from theses low power circuits though. LEDs sound great at only 10 mA each, until you need a lot of them for bright task lighting, let alone if you want a 3-color setup for varying light color.

I've been looking into this a bit more. I used to think that, under the hood, all xenon UC lights were low-voltage, and that it was just a question of whether the transformer was internal or external; for a long time I couldn't find anything to contradict that idea. I've since found some xenon UC lights, such as one line offered by Pegasus, that are truly line-voltage. So, it turns out I was wrong. Sorry for any confusion I might've caused. Some low-voltage fixtures are open-air arrangements, which I think would dissapate heat into the room more efficently and not seem as warm. Some low-voltage fixtures require remote transformers, the installation of which is a bit more complex than simply connecting a complete fixture to standard household current, so low-voltage installation may be a bit more time consuming and/or expensive. Line voltage fixtures are dimmable with cheap, common dimmers, whereas dimmers for LV lights are considerably more expensive. The most important thing to be concerned about might be the thickness of the fixture. I just scanned Kichler's offerings, and their line-voltage fixtures are an inch and a half thick while their low-voltage fixtures are only an inch thick. That could make a difference, depending on the height of your light rail.

Annab6. Mine are open fixtures. Each lamp is rated at 10 watts. The lamp holders attach to a flexible cable and can be spaced as close together or as far apart as you like. Mine are at 6" intervals. The light projected is very even across the countertop. It is not super brilliant, but more than sufficient to evenly illuminate the countertop that would otherwise be shadowed by the upper cabinets. The light is a very pleasant and natural incandescent white color. Excess heat is not something that I've ever had cause to think about. They simply don't give off much heat. The xenon lamps are also dimmable. I have the under-cabinet lights switched on more than any other lighting in the kitchen. As soon as the sun goes down, the under-cabinet lights go on. When I'm cooking, I also turn on the recessed halogen fixtures that are mounted in the ceiling over the countertops. When I'm done working, the ceiling fixtures usually get dimmed or turned off, but the under-cabinet lights remain on. They remain on until I'm turning out all of the lights in the house at bedtime. You can see an image of the lamps and fixtures that I have in the link below. Here is a link that might be useful: Sea Gull Linear xenon lamp & fixture