Did you buy one of those planters..?? I did find this video from Everything Attachments which shows one operating.
The design using the cups to pick up the potatoes out of the hopper is nothing new but works well. About a year ago I bought a Champion potato planter that uses cast iron cups to pick them up out of the hopper. It was patented here in the U.S. in the late 1800's. This one was originally horse drawn and a previous owner converted it to IH single point Fast Hitch, perfect for my Farmall 140 & 130 w/FH. It's in good enough shape mechanically, basically all I had to do was oil, and grease it up.
I normally use #2 seed potatoes to save the work of cutting them and I must say they worked very well in my planter. Our local tractor club usually plants around 300 pounds at the County Farm Park where they let us plant several things for Harvest Days in late Sept. People are free to come pick up potatoes the day we dig. Anything left over is donated to a local food bank.
Last Spring I offered to bring my planter to plant them. The club has an Iron Age converted from horse drawn to a tongue to pull with a tractor. It has the carousel type pick-up. and pretty much takes a person riding on it to make sure the carousel is full. Being I'm a 1 person operation here the Champion looked to be a better option to me.
Last year we had a hodge-podge of potatoes. Reds and yellows of different sizes. Some cut, some #2 size. They were all thrown in the hopper together, so I just hoped for the best. I must say it did very well, we planted a little over 300 lbs. in about an hour. One of the guys in the club took a video of us planting part of one row and got a decent close up of it working.
I wouldn't be afraid to try one of the newer Spedo models. The design as far as the pick-up cups is well proven and works better than I imagine. I might suggest calling Everything Attachments located in North Carolina Everything Attachments | Skid Steer Attachments, Tractor Attachments, 3 Point Hitch Attachments, and Farm Tractor Implements. since they did sell them, but now shows unavailable. They may have a list of customers they have sold one to, that you could call and get their opinion.