Here's my report about the Twin Turbo III:
Working with the thing felt pretty ghetto. I used it on an RX 580 for a while.
The card's PCB was bending like crazy when I was tightening the Twin Turbo's heatsink onto the GPU core. I think the Twin Turbo's design is missing a good mounting system to prevent this problem. Another thing I remember, there's four small plates where the screws for the heatsink go in on the back, and those four plates bend easily if you tighten thing too much.
Then working with that thick backplate was weird. There was this plastic foil that needed holes cut into it where you'd chosen to put thermal pads, that felt ugly. Then there's a bunch of clamps that go around the edge of the backplate and PCB and I guess are supposed to help keep the PCB from bending. This doesn't exactly work well, and it also hits parts on the motherboard around the area of the PCIe slot.
Overall the card's PCB was bending in all kinds of strange ways: there was the heatsink mount pulling it a certain way, and then there were the thick thermal pads between the PCB and backplate adding pressure, and then there were those clamps on the outside pulling a different way.
Performance of the heatsink was very good. The core temperatures were pretty low with it. The fans are great and don't have any weird noises. I was just worried about the VRM and memory chips. I don't trust that backplate method for cooling those.
I had to remove the Twin Turbo III later because I moved the RX580 onto a system with a X470 Taichi, and there the PCIe slot was too close to the CPU socket and the backplate was too thick to leave room for the air cooler I use.
Overall playing around with the cooler was fun for me. I wouldn't use it on a new and expensive card, but with an old card I felt it was just fun. I got the cooler for 38 EUR and that was okay.
I also used the previous model "Twin Turbo II" on a GTX680 in the past. That model had no backplate. Instead it came with a lot of differently sized aluminium heatsinks and a tube of thermal glue. I liked that better. The performance on the GTX680 was also very good, same as with the RX580.