The Medela Nursing Stool is certainly not a must-have in the long list of "stuff" that a new baby seems to require these days. But if you're making a registry, or can spare the money, I do think it is worth having to support the daily nursing experience, especially in the early days.
I first encountered the Medela Nursing Stool at the lactation center with my first baby. It was certainly comfortable, and I got the message that a stool was helpful when breastfeeding, which was helpful. But I was feeling nervous about spending money with a new baby at home, and we had just been given a cute little puzzle stool with the baby's name on it as a gift. So I just used that. A regular stool worked fine, but it was a little high and I usually had to rest my feet on the edge to have them angled, or press into the top to give my thighs a rise, which gets tiring over time.
For my second baby, since I didn't need much else, I treated myself to the Medela Nursing Stool. Having used it now for more than 2 years, I really do wish I had just gotten it to begin with. The little non-stick feet were really helpful to keep it from sliding around on the floor, and the slanted surface makes a big difference in comfort. I found it to be pretty easy to clean (you will need to work a bit with a sponge or a baby wipe to get into each of the little grooves on top, which are designed to keep the feet from sliding).
I have the light oak stool, which goes pretty well with any sort of light wood décor. When I bought mine, there was a white wood variety available as well, although I don't see this now available online.
For those who want more options, KidKraft appears to offer a version that looks pretty similar, with a slightly different design. I haven't used it personally, but I imagine it offers basically the same function. It costs more than the Medela version, but appears to be offered in more colors (white, cherry, honey and natural, that I found) to match the nursery or other rooms where you might keep a stool. I've included links to both stools below, with photos, so you can see what they look like. At the time of writing this article, the Medela Stool was available for about $25 including shipping, and the KidKraft stool for about $40 including shipping.
I think the Medela Nursing Stool, or other brand with the basic features of a slanted, grooved surface and non-slip floor pads, makes an excellent baby shower or new baby gift (I gave one to my best friend, along with copies of my favorite baby books and to another friend paired with a Barenaked Boppy Pillow).
If you are buying for yourself, while it may seems like an unneeded purchase, I found that I've spent more money on things that I use a lot less often with much less benefit, and I'm only sorry I didn't get it the first time around. After use, mine is still pretty much like new, so I imagine it has a pretty good resale value as well.
Here's pictures and links for the Medela Nursing Stool as well as the similar KidKraft variety:
Medela NursingStool - Natural Oak