I don't have it in my D2 yet. Taking my time on the install and making some nice brackets to mount it, etc. But I did help two others with the electronics, so I know the electronic setup works. I drove one with the base map at 5% shift firmness (slightly more firm than stock) and it is more lively and the shifts are more positive. Instead of shifting regularly under mid acceleration at 2500 or so normally, it was more like 2800-3200. It holds gears a little longer. It changes how the Disco drives a bit, but overall I would say it is fairly sizable improvement, depending on what you want. Stock disco with stock LS, probably not really worth it so much. Heavily modded disco with modded LS, then probably useful to get the most out of the engine, and compensate for tires, etc.

The software is pretty easy to use. It works out of the box with some basic settings, but if you want to get really into it, you can. Sort of like HPTuners, but for the transmission.

I feel like that one on eBay is somewhat pricey, but it also has the display. If you want it, I'd see maybe if the owner would take less.