Rep Cal, I think there is less of a chance of your leo overdosing on vitamin A should you use the multi-vitamin. Rep Cal's calcium is also better in my opinion, sticks on the crickets better.
I like the fact that Rep-Cal can be mixed with water and made into a paste for an extra calcium supplement if needed. It's great with assistance in the treatment of MBDs. I don't think you can do that with Reptocal.