Bupa Hero VHIS Plan - Core and Manulife Supreme Lite VHIS Supplementary Benefit - Smart are both High-end VHIS plans; they differ in ward class, benefit limits, geographical coverage and premium.
Bupa Hero VHIS Plan - Core suits you better if you value a higher annual benefit limit (HK$5,000,000) and a lower entry premium (about HK$10,532/yr at age 40, non-smoker). Manulife Supreme Lite VHIS Supplementary Benefit - Smart suits you better if you value a stated lifetime benefit cap (HK$19,625,000).
Neither plan is categorically better — your choice should rest on your own budget, where you expect to seek treatment and your family needs, ideally after a financial needs analysis.