I only use RUs if I can confirm R class is available. Occasionally the phone staff have claimed they can't check for R class anymore. Generally they're really helpful and tell me whether they're available for multiple dates and even routes. These days they say they can't clear RUs themselves and can only lodge them and wait for "the robot" to clear them. So there's a short period after confirming R class availability when you have to hope no one else lodges RUs, whereas you had more immediate certainty in the past. But I won't be using RUs or flying NZ longhaul while their PE prices are so freaking expensive. Unless you're beholden to NZ, there's no real benefit to RUs when you can buy J outright on other airlines for prices comparable to NZ PE. It depends on the route, of course, but I only travel for fun so can adjust where I go.