mcassel, I think part of the info you're missing is this: The MR in MR16 stands for Mirror Reflector. The AR in PAR stands for Aluminized Reflector. Highly polished mirror reflectors are able to direct light in a very focussed, controlled way, so the light the bulb produces can be directed to in a very specific direction (yielding a high candlepower in that direction but throwing little light off to the sides. This effect is increased with low-voltage bulbs because the filaments are smaller. However, the tightly controlled beams that are native to these bulbs can then be softened and adjusted with optional diffusing lenses that dim4fun mentioned. Aluminized reflectors are much less polished and tend to scatter the light, so less of the light is concentrated in the middle of the beamspread, and more is sent off to the sides. If you want dramatic, spotlight-like effects then the MR bulbs are the way to go. If you want softer-edged light, or if you're trying for even lighting, where the pools of light from adjacent fixtures can blend together somewhat seamlessly, then PAR lamps are probably the better choice. If you want soft light but need especially small or versatile fixtures then MR-types with diffusing lenses might be the solution.

Nora is perfectly fine. I've been using them for over 10 years with no problems. As for #2, I'd say that those trims normally do look pretty much the same. But that might vary slightly by manufacturer.

Hi there, Here are my views/ experiences: 1) Low voltage bulbs generally project less heat than line voltage. They also last longer (even much longer, depending on the bulb). A 50 watt low voltage halogen bulb is a little brighter than a line voltage halogen bulb. Low voltage cans are available in smaller sizes than line voltage. The con is that low voltage is more expensive- there's a transformer to buy. But taking into account the smaller size, longer life (up to 20k hours vs 2k hours) less heat projection and brighter light, I always go low voltage when there is a choice. Now, if you have 30' ceilings, that's a different story. But for most homes, lv works great. 2) Not really. Kitchens are very task oriented. So the cans will be closer together over counter and other work areas to give good overlap and eliminate shadowing. But over walkway areas, they'll be farther apart. 3) Cable and rail halogens do offer a lot of flexibility. You can not only slide fixtures to move them, but add more very easily if needed. There is also a design issue. What do you want to see on your ceiling? I have rail in my hall, but recessed (3" low voltage) in my kitchen. Basically, every lighting design I do involves low voltage cans. As I'm in California, I'm forced to use LED for kitchens and bathrooms. Which are great units. But in a design sense, the low voltage allows for the smallest hole in your ceiling without sacrificing brightness or coverage. There are always exceptions, but for the most part, you can light up a room using the same number of 3.5" low voltage halogens as you would with 6" halogens. The light would be the same (if not better) and the overall heat in the room would be much less.

What I have now is low-voltage xenon lights with internal transformers inside each fixture. I'm looking at replacing them because of continual problems, like multiple burned-out bulbs and a burned-out transformer after 16 months, and innards so full of wires and wire nuts that the fixtures pop apart if I removed the glass diffusers (or spontaneously in the case of the smallest strip.) Judging from online reviews, these are common problems with the model that I have. We have line voltage coming out of the walls for the three separate runs of lights, all on the same circuit. If I understand correctly, the electrician can use the existing wiring to install either low-voltage lights with internal transformers (NOT the same brand!) or line-voltage lights. I bought the lights we have based on looks, function, and the showroom salesman's recommendation. Never would have thought to ask to see the inside of the fixture, though.