In our guest bathroom we have a 24" vanity (it's a small bathroom) and discussed mirror width. We ended up going with just the width of the vanity, thinking it would look strange if the mirror were wider. I don't know if that helps you, though. The mirror won't be super wide, but it seemed that it would still be wide enough to see yourself in. In our case it's not a cabinet, though, just a mirror, so you do lose storage space in your case. Could you add additional storage elsewhere? Maybe add a shelf somewhere in the room?

UCL is best for task lighting. In addition, it can effectively replace the main lighting under certain circumstances - early morning, late at night. If you want a soft light, the light output color should be 2700k. UCL Installation would be greatly helped if your kitchen cabinets have flat undersides without any interrupting fences. The rough rule of thumb I used for my kitchen was ~35 lumens per sq ft. Total area * 35 gives you the total illumination required. Divide the total by the output of each can (assume 600 or 500+ lumens per can) if all the lighting is envisaged to come from the recessed cans. A normal 60W incandescent bulb outputs ~ 800 lumens, but when put inside a can, the effective output is significantly reduced. If you use a LED recessed can light such as the LR6 or CR6, the lighting will be superior to a standard recessed can light (incandescent or CFL). Recessed cans are typically spaced ~ 4' apart. However, if necessary, the spacing could be reduced to 3' for areas such as the kitchen. The recessed can in the keeping room could be replaced with some surface mount / chandelier/ pendant.

It's just not possible to have too much light, in my opinion. I've never been in a house that was too bright. When we were planning our kitchen gut, I added cans, pendants and undercabs. All the cans got switched up from dimmer to switch for one reason: I wanted to be able to use CFL bulbs to save on electric. These require a different fixture. The cans that can use CFL bulbs on a dimmer cost ten times what the switch ones cost. Hence, I got no dimmers. The old kitchen had two ceiling mount fixtures with four flourescent tubes each. The new kitchen has twelve cans in the ceiling, six pendants over the dining table and six pendants over the peninsula. I have CFL bulbs in every one; all different colors of light; none burn hot. We have four cans to one switch and 3 pendants to one switch. If it is too bright (which is never) I can always turn a switch off, (but never do). Having that much light in the workspace is just AWESOME! Yes, our neighbors think we're growing pot in the house. Yes, our electrician made fun of me the entire time he was working on it. No, I wouldn't change it! My cataracts no longer inhibit the activities I can work on in there and I think the food even tastes better! I'm planning on cutting more holes in the ceiling in the living room, and the little bedrooms if we ever get that far on the renovation! We're saving a bundle of money on the electric bill and don't have extension cords with lamps attached and cords to trip on anywhere anymore!!! In addition, we got the can fixtures that keep the bugs up in the attic from coming thru the ceiling. Nice huh? No more cricket carcasses like in the old tube fixtures! I won't ever have to worry about cricket legs or spiders coming down from the ceiling onto the dining table ever again. It's just wonderful! The undercab ones we got are halogen. They do burn hot and suck electric. Those I would change in a heartbeat. I worry about warping the cabinetry & my spices going stale so I don't use them much, except as a night-light when one of us is getting home late. The color of the light coming from them is yellow-er than the other ones and I don't like it as much. Another thing I hate about the undercab lights is the transformers take up space inside my cabinetry. What I love about our undercab lighting is that our electrician was able to hide all the wire so you cannot see it & it illuminates the back corner areas that are so dark. Seeing all the way to the corners is awesome & lets me use space I would ignore otherwise.

My rule of thumb for lighting is you can never have enough and you can always dim it if you want less. For your master bath I would do at least 4 recessed lights (RL) for the main area, 2 RL in the shower and 1 RL in the tioilet area. For the sinks either 2 sconces on the sides of each mirror or a 3-light over the mirror light. All on dimmers. In my powder room, which has no windows, I have a fancy semi-flush chandelier and 2 RL. I would do 8 RL in the kids bathroom and either 2 sconces or over the mirror lights at each vanity. Don't forget fans.