Extremely lightweight Compact
I used to forgo bringing stakes since I had a freestanding tent, but since these are so light, there's really not much of an excuse to not bring them along. I have used them on a few backpacking trips now...with my non-freestanding tent, they are essential and perform just as well as aluminum stakes.
The compact design slides nicely into any crevasse in your pack, where you may just forget they are there. They work pretty easily into hard packed earth, but in the Rockies, I had to try a lot of spots to find a rock-free dirt patch. Also, I wouldn't want to take a rock hammer to one of these for fear I would break the plastic or carbon. Even though they were part of a prize, they are dear to me and I feel the need to treat them pretty gently.
Lastly, they held well once sunk but could be a bit longer in some circumstances. They don't suffice in sand, not even close.
Overall another very nice product from MSR, incorporating innovative design and materials.