There is a huge difference between recessed lighting and spot lights. The typical MR16 or equivalent has a angle of light which varies from bulb to bulb including how shape the cut off is. Using a angled spot light aimed at a white wall will light the room far better than one shinning down on a dark floor.
I have two small spots either side of the bed head which as standard shine to allow reading a book in bed. As an experiment I instead aimed them at the white ceiling and these two very small spots actually did a good job at lighting the room. To my mind the problem is we carefully select the angle of the units and order them all off the internet to start with, then one fails and we replace with one from local shop so all our careful calculations are ruined.
So to start with you need to design around what you can buy local. Second is of course look at the colour of floors, and walls or any other surface the light will be bounced off. In essence the lights are no good to directly light the room, as I showed with my experiment as wall up-lighters they worked well. Surface area matters, this is why the fluorescent tube does such a good job. There are larger recessed lamps around 10" which either take 2D or CFL in them which work better than the spots because of surface area.
My son has a very small kitchen and he used 5 x 7W LED spots, and I had to get touch out of the car to read the display on the boiler. My living room has 10 x 3W LED lamps all candle and pointing up to white ceiling and there is ample light. It's not the watts or lumen that matters it is the spread. Had my son used 10 x 3W LED spots although less watts he would have got more light.
Fitting is another problem, he removed the ceiling plaster board, installed wet under floor heating in some rooms from below, then fitted the rock wool to reduce sound, and marked and made a detailed plan of where the lights would be fitted the boxes and cables for the lights, then replaced the ceiling, then using the plan cut holes and fitted lights. Yes living room worked out very well. But that is a lot of work, hardly worth it unless new ceiling is required anyway. He has nearly finished, it has been three years, had the mortgage people found out he would have been in a lot of trouble as during the work the house value clearly dropped. Yes now it is great kids can do what they want up-stairs you can hardly hear them down stairs.
A box like this
will not fit through the hole drilled for the down lights so either floor board need to come up or ceiling needs to come down. Or you botch it all and wreck the house.
