BigIP LTM 10.2.3 -> 11.3.0 upgrade - configuration issues

I had to run the same command in order to restore config, but then, I started noticing those discrepancies in node definitions. I didn't even go that far to check the rest of the config items before rolling back. What really bothers me is the fact that F5 doesn't say a word about 10.x/11.x incompatibility and doesn't provide any additional hint/articles on possible issues that may occur during the upgrade process. Another issue is that once the upgrade process is completed, there's no sign of report/warning that would tell end user about config not being processed at all. Looking at their 'upgrade howto' document, one would say upgrade is an absolutely straightforward process. Worst of all, even after three subreleases, they still didn't address this problem.....