Hello,
I recently had to migrate some comments from Hikashop to Komento.
There were several issues with the Komento custom migrator and the guys at Stackideas did a great job helping me.
If you have a valid Komento subscription, you should be able to access this forum post:
stackideas.com/forums/custom-migrator-not-working-for-hikashop
where you will find all the necessary info and patches to fix the migrator and migrate all your votes/comments correctly.
Hope this helps!
P.S.
you will need some basic knowledge on how to modify some db tables as well, because Komento stores ratings value in a different way, but it's really easy to do, I used "Regular Labs DB replacer" extension which is great for such quick edits
