Roborock will launch an entirely new high-end line of robot vacuums in April with better suction power, a tangle-resistant roller, and a new dock in the top-end model. Announced at CES on Wednesday, the S8 series will start at $750 and includes three models: the S8, the S8+, and the S8 Pro Ultra (pictured above). The most significant change in the S8 series is the available suction power. The S7 series vacuums each offered about 2,500Pa of suction, although the S7 MaxV series more than doubled that to 5,100Pa. The S8 series vacuums have better suction across the board (6,000Pa), while a new du…