It's good for the price, but it's more like the H510 is bad - for airflow.
AIOs do best when placed against mesh panels. With a 240mm in the H510, you end up choking the crap out of the fans as well as reducing air intake to the gpu and other components in the PC.
Air cooler got an edge in that chassis. It's closer to the center, so its fan(s) has more breathing room, and it's not further restricting front air intake.
That said, the H510 supports front mounted 240 and 280mm AIOs, with the exception of Arctic's Liquid Freezer IIs; the rads are 38mm thick, making for a total of 63mm thick. The max front clearance is 60mm.
Most other AIOs have 27-30mm thick rads.