I use this all the time for a lot of reasons... it's small and portable, it's fun, it takes less time than spelling everything out with larger stamps using one letter at a time and, because it's smaller than most alpha stamps, you can use it in spaces other stamps wouldn't work (like on tags or in journal boxes). Also, you can use it for more than just alphas. There are also words, ornaments, etc. that can be used with this base. I keep mine handy and would suggest you do the same.
I really have fun playing with this set. I like how the letters are alot smaller than other stamp sets so they fit in places on your layouts where other stamped words maybe wouldn't. I have to be honest, I don't use this as much as I originally thought I would. It does take some patience working with the tiny letters, and it is easier to me alot of times to grab the bigger stamps, but I do think the tinier letters have a place and are very useful sometimes. I also have alot of trouble getting my words straight with this, which I actually end up loving because it has a fun playful look, but for someone that is a perfectionist this might be something to consider. This set is super easy to store and take-along in it's own self-contained container, and I am really glad I have it as an option. Overall, I am very happy with it!
I have used this product with my rummage letters many times over. The other day I was working on some recipe card dividers and the label holders on the dividers were pretty small, so no letters I had worked. I remembered my letter stamp set and it worked perfectly! It comes in a sturdy case great for taking to crops outside the home!