RX550 jump from 460 to 545 h/s
RX560 no improvement for me , i try with and w/o L
edit:
rx560 i manage to overclock high . +20 core and +25 mem , that about 1% hashrate improvement
Yes, the 550s are really the big target with the L option. It has the largest improvement on 8CU and 10CU cards.