Okay, I've finally got some pictures. I decided to wait until I unpacked a few figures. In this picture, the Barlighting strips are on the left, and on the right are Ikea Dioder pucks.
The Barlighting lights are a bit cooler than Ikea's old cool white lights. It works for my purposes, but I'm not sure the two types are a great mix for general use. The Barlighting power cables are much shorter than Ikea's, which meant that I had to drill a few holes in the bookcase backing (three per bookcase), but you can chain them together so there are fewer visible cables in the shelves themselves. You can see a bunch of the Ikea cables in the right bookcase (especially in the second shelf down), but the Barlighting ones are harder to see. They're all in the right back corner of the bookcase; you can see the one on the top shelf if you squint at it.
I'd say that these are a nice replacement for Ikea's now useless Dioders, but I wish the Barlighting cables were longer (and came in black so I didn't have to paint everything).
Here's a wider shot, with one side of my eventual shelf setup. The Dioder pucks are in the two bottom cubes of the far right shelf and in the entire wide shelf to its left (third from the left). The rest are Barlighting.
In case anyone is interested, I mounted the lights on a wooden mounting strip that I made from two pieces of precut balsa from a hobby store. For each shelf, I used a 30" x 1/2" strip and a 30" x 1/4" triangle, which I glued together. In the pic below, the left edge is what was mounted to the bottom of the shelf, with the bottom in this pic facing out.
I then glued the light strips' mounting clips to the slanted edge and attached the strips so that the lights are angled into the shelf. I painted the outside face black and attached the entire assembly onto the bottom front lip of the shelf with double-sided tape (3M exterior). The wires are run to the back of the bookcases, then to a remote-controlled power strip so everything comes on with a switch. The strips are a bit fragile, but they don't look too bad.