There was a very similar thread about this same question in the last coupe of weeks. You might search it out. But the general consensus is that if you have the room for them, use the cans with an LED kit has it gives you the most options, and will likely be around for many many years. The wafer lights are pretty new, and non-standard size so if one goes out, will you be able to easily replace in the future? The wafer kits however do provide you more flexibility, and can be great for your top floors against insulation as they don't add a large void in your insulation space.

I've put some of these wafer lights in our bedroom and closets on the top floor because they are IC rated and have zero dead space within a housing and so far they've worked great, and were a breeze to install. The longevity will of course be the question. I did go with Halo for the most of them as they typically make a quality product.

If this is in a cold climate and is the ceiling of a first floor space, traditional recessed cans can cause problems with air and heat leakage that might cause other problems such as ice dams, condensation or higher heating bills. See https://www.greenbuildingadvisor.com/question/recessed-can-light-alternatives

Thanks for the input guys. Good point about the led wafer lights needing to be replaced and finding a match. It can get cold here so insulation is a concern. Zone 6 I think.

You need ICAT housings. Not just IC housings. And caulk arounfd the penetrations. But the new ceiling discs are even more functional than recessed, with no penetrations other than a standard electrical box. That makes them far more versatile, as the electrical box can supply any type or size of surface mount fixture, now, or in the future.

Properly done, lighting can add both functionality and flair to a home. 30 years ago a typical electrical plan might have included a couple of recessed cans, a few surface-mounted fixtures and some ceiling fans. Today, the available options for lighting are mind numbing (at least to this non-lighting designer.) Plus you need to figure on power to charging locations for the various portable electronic devices, TVs, etc. that dominate our daily lives. These are best done in the design phase-- not when the electrician is roughing in.

I suggest that you would be well served to have a lighting designer/lighting consultant take a look at your plan and offer suggestions based on your specific needs. Some lighting showrooms offer this as a free service to their customers, some architectural firms have the expertise in house or you could hire an independent lighting designer.

Best wishes for a successful project.

I really like the idea of the ceiling disk light that uses a standard electrical box, but should I be worried about replacements when it needs replacing in the future?

The ultra thin LEDs are inexpensive. If you are concerned about the availability of spares in the future, why not simply purchase a couple of extras now?

As RES points out above, the concept of recessed lighting fixtures is that the light source is not visible or seen, but the space or task area is properly illuminated.

The surface mounted disk lights are obviously highly visible and create a distracting "hot spot" on the ceiling. IMO, these types of lights should be relegated to under upper cabinets, the garage and other places where the visual appearance doesn't matter.

To be sure, no single light fixture is the right prescription for every application.

Where ultra thin LEDs shine (pun intended) is in dropped ceiling applications, showers, vaulted ceilings where insulation thickness is a concern, and in locations where framing interferes with installation of a "conventional" recessed light fixture. I used ultra thin LEDs in a recent remodel where the owner wanted to add recessed lighting in a hallway and an existing beam interfered with centering conventional recessed fixtures.