On the tail end of the video at this thread you can see some other designs. They have a spring block behind and water flows around them. All harvested cacti (not 100%) go to same spot. I am going to try to make one where the water flows over the first level of cactus.
-If a cacti lands on itself, it is destroyed.
-this may work with reeds?
The Meaning of Life, the Universe, and Everything.
I figured this out by accident when I created a pig spawning/killing room. I stood in the collection area and browsed the internet a bit, and when I came back I had an inventory full of pork and a few cacti.
I made an XL version with a meager 2 water springs and 16 cacti.
...Well, I sure can't beat your efficiency or cleanliness of design, but I can beat you in the area of ridiculous excess:
That's the array of 22 (magically water-repelling) collection platforms for my field of 82 cacti, which is packed so densely I can't screenshot it. It spits out around 50-60 cactus bits every 10 minutes, and has giant holes in the walls to catch the occasional surprise. All the water pipes are glass-bottomed, so you can hang around in the collection room watching cactus bits drift down to their designated platforms.
This thing could completely fill a small chest with cactus chunks in a few hours. Not that I have any idea what purpose that would serve.