OEBTs are selectively bred from regular tigers (wild form) so there's more inbreeding with OEBTs, therefore, they will be weaker then regulars. My OEBTs are pretty hardy though. This is how I'd rank the shrimp in terms of acceptance of water parameters:
Regular Tigers > OEBT > CBS/CRS, depending on grade, > TB
Regular Tigers > OEBT > CBS/CRS, depending on grade, > TB