Who are HK Express trying to target with these perks? If it's the regular traveler with status elsewhere, they will not care about the perks unless HK Express is pricing U biz below typical FSC Y fares.
If they are targeting the leisure traveler who thinks they are getting J class for LCC price, both HK Express and the travelers are delusional. With so many credit cards offering access the Plaza Premium Lounge in HK is almost like a food court (sometimes worse when you see people stuff their bags with free drinks and the line up to get in). The $25 voucher can get u a little more than a bottle of water on the plane (ASAIK their meals go for about $50 - $70).