You ask "What's the performance difference between this two differential amplifier?" but I think what you really meant to ask was "What's the performance difference between these two current sources?".

The first circuit performs better because it amplifies the sensed voltage directly. Though, the OP07 may not be the best choice. They make specialized ICs to sense the current in the positive rail: https://www.digikey.se/short/8ftfz4n0

You ask "What's the performance difference between this two differential amplifier?" but I think what you really meant to ask was "What's the performance difference between these two current sources?".

The first circuit performs better because it amplifies the sensed voltage directly. Though, the OP07 may not be the best choice. They make specialized ICs to sense the current in the positive rail: https://www.digikey.se/short/8ftfz4n0. For example, the AD8212YRMZ

For starters, those are not differential amplifiers. They are op-amps.

You ask "What's the performance difference between this two differential amplifier?" but I think what you really meant to ask was "What's the performance difference between these two current sources?".

The first circuit performs better because it is not affected by the voltage. The second circuit suffers from the tolerance in the resistors in the voltage divider.

You ask "What's the performance difference between this two differential amplifier?" but I think what you really meant to ask was "What's the performance difference between these two current sources?".

The first circuit performs better because it amplifies the sensed voltage directly. Though, the OP07 may not be the best choice. They make specialized ICs to sense the current in the positive rail: https://www.digikey.se/short/8ftfz4n0