My horse is an easy keeper and like Loosie said, easy keepers don’t really need extra grain. My horse only gets an RB as a way to round out his supplements and make sure there are no deficits.
For peace of mind I plugged the data on all the available RBs in my area through FeedXL and the scores were right on target. I narrowed my choice down by a few minor personal preferences and reliability in terms of being able to get it fresh when I need it, which is only one bag every two months.
It's been 18 months since I made the switch and my horse is sleek, shiny, and has terrific hooves.