I have the NT520 Pro.

I've used it for a few things:

- Monitoring ATF temp when doing a fluid drain.

- Reading BMW specific trouble codes.

- Diagnosing problem with alternator / charging system.

I got mine on eBay and saved a few dollars by making an offer at the "if you buy 4 price". I think that was around $126.

It works well, but the documentation is skimpy. It doesn't show clearly which modules you have when drilling down through the menus. I think there are three different transmission modules I can select and then get the same information. Each seems to work the same way. (I know I have the 6-speed in my N62).

There's a procedure for bleeding the brakes with the ABS, but I don't know how it works. I'll look that up when I do that next year. In the past, I've only done the manual two-man method.

I can reset the transmissions adaptions, but have held off since the transmission is behaving well after doing three drains/refills and I don't want to mess it up.

I did one online update, but the latest changelog only showed a minor update for Z4's. It wasn't clear if there were any intermediate updates from the version I was starting with.