Scalping on BF during Cheltenham is quite difficult imo. Both sides chock full of money, low fill rate, and nothing much happens for ages.
Daq much better suited to scalping festival. Less money in queue, better fill rate, plus you get .1 price increments, so you get 6.1 6.2 6.3 6.4 6.5 etc where on BF you just get 6 6.2 6.4.