No major issues. If you're moving from a single node PG to CRDB you should expect CRDB to be slower because of all the consensus stuff. However almost every update I see from them contains some improvements in that area so it will get better with time probably. You just need to figure our if you're willing to accept a 2ms - 1m (PG) query execution vs 20ms flat execution (CRDB) - even after all the optimizations.