JEDEC reference PCB (LEFT) vs BrainPower PCB (RIGHT)

From the pics, BrainPower PCBs seems to be :

1. "empty" at the middle of the PCB
2. less trace route between chips and power leads (the "gold fingers") on SIDE B
3. shorter height

Also, there are 2 types of BrainPower PCBs :

1. B6U808
2. B6U815



tak do jakých pamětí kdo pude, ty A-DATA budou asi nejlevnější a nejpřístupnější co?