These cards are a great resource for anyone interested in lace knitting, but a bit apprehensive about making the plunge. The directions are well written, easy to follow, and include written instructions as well as charts (helpful for anyone learning to read charts!) The cards are a great size for slipping into your knitting bag, and sturdy enough that you needn't worry about them getting crumpled.
If you have any lace knitting experience, you will likely tire of these cards quickly. While the simplicity of the patterns is great for beginners, experienced lace knitters may find that simplicity boring and repetitive. There are a few stitches that are fresh and fun, but most could probably be found in one of the numerous free stitch libraries on the internet.
Bottom line: If you're new to lace knitting, these are a great way to get started. If you've had some experience with lace knitting, you may enjoy these as a reference, but would probably be happier with something a bit more advanced.