My use case will be for Mercedes, Audi, BMW and maybe Ford. While it is nice having dedicated STAR, INPA/PA Soft/NCS-Expert (BMW), VAG-COM (Audi) and FORScan (Ford) setups in my garage, I relish the idea of a powerful, activation-capable, all-in-one to take with me on the road. Foxwell NT510 Elite multi-system scanner is the best one to go for.
For Mercedes Benz: the Best
When you purchase the original unit NT510 Elite you get one manufacturer free of charge (I bought Mercedes). My daily is a Volvo V50 so I have subsequently paid Foxwell extra and now bought Volvo, which is now also on my unit. So my unit can do both Mercedes and Volvo.
Ive found that the Volvo software is not as good as the Mercedes Software. It hasn’t affected the Mercedes use at all though. The upload of Volvo adds an extra “Volvo” button onto the initial user interface so on start up and plugged into the car you just use the appropriate manufacturer button from the initial interface.
For Mercedes Benz, the best and can compete with Star Diagnosis
I've been a regular user of Star Diagnosis for a dozen years. I own a Foxwell NT510 Elite with Benz software, and it does practically everything I have ever used Star Diagnosis for. And as a bonus for a small fee Foxwell can be expanded to work with other makes.
The Jaguar software I added for $60 yesterday isn't as good as the M-B software either.
The Mercedes software is obviously based upon Star Diagnosis given the menus, their paths, and contents are practically identical.
For BMW, Audi, Mercedes: the Best
Foxwell NT510 Elite BMW and Audi functionality is confirmed to be solid as well. If this tool covers a fair bit of manufacturer-specific functionality for the "3 Germans", good enough for me as those are the brands I am focusing my hobby on.
I also have a well-rated wireless OBD tool (and a few of the well-known apps), but they all have generic functionality. Good to scan/clear basic codes and monitor some real time data (was helpful in tracking IATs when modifying an M113K car) but that's about it.
For Aston Martin, Mercedes, Audi, BMW: the Best
I've had a Foxwell 520 for over a year. Original purchase was based on it's ability to access essentially everything in my 2009 Aston Martin DB9. I was very satisfied with it's functionality on that car, so expanded it to Mercedes ('03 SL55), Audi (2013 A8), and BMW (2007 Mini Cooper S). It doesn't do everything on the Mini, but does enough on the other cars to continue providing good value. I do have an SDS system, but find the Foxwell more convenient.
Foxwell NT510 Elite BMW reviews
Foxwell NT510 Elite Benz reviews