What your electrician is suggesting is a surface-mounted fixture that is about the size of a dessert plate. It uses an LED source, which is dimmable. My main concern about this type of fixture is that is does produce quite a bit of glare. A more traditional recessed fixture does a much better job of hiding the light source. Using an airtight recessed fixture does keep heating and air conditioning from being lost through the openings created by the installation of recessed fixtures. The shallow LED "dessert plates" are airtight since they do not pierce the ceiling. You could easily change out these fixtures to another surface-mounted fixture or a pendant-mounted fixture from the existing J-box.
My recommendation, though, is to go to a more traditional recessed airtight fixture that uses an LED source. You want to pick one where the lens that hides the LED diodes is regressed back into the fixture so that it is not flush with the ceiling plane. There are a lot of manufacturers out there. I would recommend that you find one that has a warm color temperature (2700K), has a good lumen output (the equivalent of a 75W reflector bulb or better) and is dimmable. Take a look at the Cree  CR4 and CR6, which fit into most 4-inch and 6-inch housings. I also like the WarmDim by Juno , where the LED lighting appears to get warmer as it is dimmed.