I think it's pretty much plug and play. The power/data cable might have to be changed, but that's about it.

Of course I might find out about some type of gotcha after I get it, but for the price it looks great. Certainly an improvement over the Lowrance HDS7 (if it works).

It's a close out, so Defender might not take it back. However, I called B&G Support just now and they say the radar and depth sensor and NMEA 2000 connectors are all "plug and play". I asked him specifically if there's any firmware/hardware compatibility issues between the Lowrance radar and the Zeus touch, and he said "no". He also said the radar menus are identical.