Serato to rekordbox works well because all types of beat grids in Serato are supported in rekordbox.
Serato does not have the concept of memory cues the rekordbox has though so there is an option to duplicate all Serato hotcues to memory cues during the sync.
Serato can support many more hot cues and hot loops so not all of them can make it thru to rekordbox (in case you are really using 16 hot cues total).
Finally rekordbox doesn't support Crates with both tracks and sub crates so this is not exported out of Serato.
Hope this helps, feel free to contact me if you have any specific questions.
(DISCLAIMER: I am the author of Rekord Buddy).