Your Autel AL439 does not list "Enhanced OBDII Mode 6" in it's features, but your AL519 does, but I have seen some retailers of Autel products say that the AL439 has all the features of the AL519 and more. Therefore can you please tell me:
1) Does the AL439 indeed has "Enhanced OBDII Mode 6" even though it is not listed specifically on your feature list?
2) What is "Enhanced OBDII Mode 6" as compared to just regular "OBDII Mode 6"?

 Thank you for the reply.  That answered my questions perfectly.
I have one last follow up question for you then.  From what I read of the feature sets of both the AL519 and AL439, if I already own a very good quality multimeter and already know how to diagnose bad battery and starter problems etc, then it sounds as though the AL519 would be the better choice for myself as it has all the features of the AL439 except multimeter and starter diagnosis (which I can already do with my existing tools), but the AL519 has the advantage of the extra features of the "Enhanced Mode 6" and "data graphing".  Does that sound correct, or did I miss any important feature?

Thanks.