You want to stay under 80% of the transformers rating, and try to feed the string from the middle, not one end. In many cases a larger wire to feed from the middle is money well spent. Dropping a volt or two on a 120 V circuit does not have much affect (less than 1%-2% voltage variation). Dropping 1 V on a 12 V circuit is over 8% right away, (and almost 16% of the power). The LEDs take DC. If they are fed a DC supply with a lot of ripple they will dim and even shut off when the voltage and current get lower than needed to operate the individual LEDs. They appear to blink very fast, often at 60 Hz or 120 Hz (depends on the power supply design). You can see the n\blinking if you sweep your eyes over them in dim light. They will look like displaced dots of light in a line. Blinking at much lower frequencies (every few seconds) usually means you have the wrong type of dimmer for the power supply. This will quickly overheat and damage either the dimmer or the power supply (one usually fails before the other). The blinking rate often varies with the dimmer setting. As you try to dim further, the lights start to barely blink off and then blink off for longer ad slower times.

5000K is close to "daylight". 6000K is going to come across as quite blue. 2700-3000K is considered a "warm white" and is close to what we are used to in our homes with incandescent lighting. One of the things that is interesting is that LEDs don't become significantly yellower when dimmed (if you are doing so) like what incandescent does. Our lighting will be a mix of temperatures - all toward the "warm white" to slightly neutral end of things. We have the Ecosmart (Cree) 4" can lights installed - those are 2700K. Our UC lighting will be 3000K. And our pendants are at 3300K. Our UC and pendants aren't installed yet, but I do expect that the pendant lights will read a bit "cooler" than the rest of our lights. Personally, at night, I like lights a little on the warm side - it seems cozier. And I'm perfectly fine with my kitchen having a different look in the day as opposed to night. Also, I will say that it was interesting going from having the 65 watt incandescents in the recessed lighting and then putting in the Ecosmart 4" (also rated as being "about the same as 65 watt"...the room is SO much brighter...extremely glad that we will have our dimmers. Over time, LEDs do fade a bit, so in my estimation, it's better to be too bright and turn them back than too dark and wishing for more light. Also, as we get older, we need more light to see, so that was another consideration as well when we are possibly "overlighting".

Good for you! I just ordered LED tape light, too, from Amazon, a couple of days ago. Total cost was less than $45. I got the 16' dimmable double density LED light strip (130 lumens per foot), a transformer and dimmer switch. Since I have only about 8 feet of upper cabs, I'll only be using about half of the light strip so a 30 watt transformer (less expensive) is sufficient. (Hopefully, I won't need any other parts.) Also ordered a couple of LED GU10 light bulbs to replace the halogen ones in the range hood. (We built the 8' run 'in place' rather than as separate boxes so there are no dividers inside the cabs and no obstructions on the bottom.) I'm planning to mount the tape lights on a long strip of aluminum--salvaged from some vertical blinds that were in the 'free pile' at a garage sale. The aluminum will be mounted to bottom of the cabs with a bit of spacer between the aluminum & cabinet bottom. The idea is that the aluminum will serve as a heat sink for the LEDS & the spacing is to facilitate heat dissipation. This will be my first experience with LED's so I'm pretty excited to see how it goes!

Glad you are still around. I've been following the lighting forum for a few years and I posted there but haven't gotten a response yet so I decided to search the kitchen forum. We redid our kitchen several years ago and we held off replacing the fluorescent under and over cabinet lighting because LED wasn't there yet. OMG I just looked it up and it was in 2010!!! Anyway, I've wavered between LED UCL/fluorescent over and LED for both. I finally decided to go with low voltage LED strip lighting for both. I see that you just have the strips without a diffuser. I was worried about the exposed strip LEDs getting dirty or banged up. We used it like you did (on an aluminum strip without a diffuser) on a project at my office but it is protected in that installation. Now that your lights have been installed for while now, are you still happy with them being exposed?