Those are the very lights I'm planning to use, if I ever find the time to finish building my upper cabs. My understanding is that xenon bulbs generate a fair bit of heat, but because they don't need a heavier glass enclosure like halogens do (halogens can explode when they fail, and have to be protected from being touched) they can be mounted out in the open like that, and the heat dissapates into the room fairly efficiently. In other words, they generate some heat but don't get terribly hot. Make sense? Fluorescents would run cooler and cheaper, and there are some very low-profile models available.

I also have the Seagull Ambiance linear lighting system and LOVE it! I did research both the Halogen and Xenon strip fixture units first and found them both to be unacceptably hot, plus were not dimmable. The Xenon linear lighting systems do not generate excessive heat because the bulbs themselves are so small and are not enclosed in a fixture case as other posters have mentioned. They use dimmable low voltage transformers and I find I use the dimmers on mine all the time. I love the ability to have a bright work light over my countertops or to have low level ambient mood lighting as the need arises. If I actually touch the bulbs with my hand they are of course hot, but the heat is not felt at all a couple inches away and does not reflect heat into my cabinets. They are exactly what I was looking for in an undercabinet lighting system.

I have t-2's in my kitchen. I love them. I used them rather than the Xenon and the halogen as they both were too hot and I do a lot of baking with pie crust and chocolate. Neither of those can stand the heat. Mine are thin, give great light and I have "warm" color bulbs in them. If I had to do it over again, I would still choose them. My contractor who is a confirmed Halogen man, now loves them too. BTW, the fixtures weren't expensive but the bulbs (the warm color ones) are. Just FYI

We are planning on the Xenon lights from Lowes too, but our concern is the placement. We may override the advice and strong recommendation of the people from both Lowes and a specialty lighting store - both of whom said that it does not look good at all to have any wires showing under the counter. They both said it would look really horrible and absolutely to not do it. The speciality lighting store had a fix - it was a box that you install at the back, while the light goes at the front, but of course it's more expensive, negating the primary benefit of Xenon. I am thinking, "who cares" to wires showing. You don't see under there anyway, and you can use attachments made to hold up the wires (or even completely encase them in a strip). So we are leaning toward mounting them in the middle front area and leaving the wires exposed - and hardwiring the whole thing. I looked under the cabinet of my mom's and it's bare wire, but you can't see it unless you duck your head down low under there. It didn't bother me and certaintly wasn't horrendous like the sales people say it will be.