The P2-300 is Single core, The Cortex-A7 is Quad core .
The P2-300 has 300 Mhz, The Cortex-A7 has 900 Mhz.
The P2-300 is CISC, The Cortex-A7 is RISC.
The P2-300 consumes 18.6 Watts, The Raspberry Pi only 4 Watts.
In other words yes the Cortex-A7 is better than P2-300.