The one downside to these is that you can't purge a keg filled with Star San in a closed pressure transfer. I remember reading that when someone tried this, it left 3-6 oz of Star San in the bottom of the keg. A pressure transfer should work otherwise but you would have to just purge the keg with CO2 and hope you got all the oxygen out.
Clear Beer recommends on their website to do an open transfer to the keg with some time still left in active fermentation to consume the remaining oxygen in the keg. This seems less than ideal if one is concerned about oxidation.