Youre right of course. My first attempt at transferring my data was through the inbuilt conversion tool within BK6 to ove from BK5. I lost far too much of my data that way so attempted to use the GEDCOM method to build the data instead with no better result. i lost all Source information for example.
I consdiered starting from scratch using the new version but didnt like it, and it was far too big a job so I uninstalled BK6, reinstalled 5.2 from my original download and then recovered from my backup and have kept with 5.2 ever since. I found BK6 had lost everything that made 5.2 different to everything else on the market.
Each to his own - there's a lot to be said for finding software you like and does the job for you and sticking with it I am sure you will agree.
My data now runs to 14500 individuals so I would not like to lose a single byte of that data and have to retrace my research steps to build it again.
I started doing my wife's ancestry afer my second marriage 2 years ago and installed Rootsmagic on her desktop which I now use as a subset consisting of her data whilst incorporating her data also into my own tree on my laptop. Rootsmagic is a good package but I prefer the ways I use my BK5.2 Currently I am thinking of installing Legacy for its charting functions which is certainly a weakness in my BK5.