This post collects some piece of opinions from experienced technicians on BMW ICOM and BMW K+D CAN scan tool, hope it helps.
Opinion1: A DCAN lead can do most things, but the ICOM is better with ISTA/D or ISTA/P
Those programs expect an ICOM unit, with the optical connector.
Most of the jobs can be done one by one with a Dcan lead, but ICOM is handier if you come across different cars.
With an ICOM and ISTA/D for example, you can plug into anything from an 8 series to an i8 and it will do everything automatically.
DCAN leads might need to be set up in K line, CAN mode, and wouldn’t work on older cars that need an ADS interface.
Opinion 2. One of the real differences is that with a K+D Can cable access to some 663 (professional) radio modules is not possible whereas with ICOM can always communicate to this module. You’ll encounter this problem using NCS Expert.
Opinion 3. Unless you are working on a lot of different BMW’s professionally, ICOM is a waste of money. a $20 K+Dcan cable will do everything you need to do on a 2007 328….
Opinion 4. Icom is more reliable for flashing modules too. Less chance of getting a security access error