I thought I'd share this with anyone interested. I just found out that the new LED recessed lights solve serious problems that exist with recessed lights, depending on where they are installed. Case in point, I have 9 of them in a cathedral ceiling. With conventional lights, that isn't good. First, the area around the lights typically has no insulation, so there is heat loss. Second, with a metal fixture, it gets cold, transferring the cold to the trim. That causes condensation in the winter. I have paint peeling around the lights. In the past, I've repainted and it's OK for a few years, but then returns. Besides the heat loss due to no insulation, there is also significant air leakage because most of these are not even close to being air tight.
So, I just discovered that LED retrofit kits exist that solve all this. They come in 4, 5, 6 inch versions and consist of an adaptor on a length of wire that screws into the existing socket. Then the new LED light gets pressed into the existing fixture. It solves the above problems. They are available in depths under 4", so there is still space for 3 or 4 inches of insulation above it. Second, they are inherently mostly airtight. Some pass an ASTM standard that says they are in fact airtight. But even the ones that don't say they meet the std, sure look airtight to me, especially if you put a little caulk under the trim before shoving it in. They are almost all made of plastic too, so transfer of cold will be limited.
They generally run about $35, but there are ones that cost more than 2X that. Lowes has a Utilitech one that is 5 or 6", 700 lumens, equiv to about a 65W, for $25. So, if you have recessed lights in a cathedral ceiling or going into an attic space, they are definitely worth considering.