When I first looked through Alyce's book, landing on this page gave me a stepping stone in an unfamiliar world, as we have often made a similar sorbet at cooking class. Ours is based on cantaloupe and pineapple frozen like this, but we only use one lime.
Making the double-lime created a very adult level of intensity. The extra sugar (normally I would only use 80g but I did as the recipe called for) also took the taste to another level - not necessarily "better" but "excitingly different".
I was surprised that the recipe asks you to pile in all the iced fruit (800g) at once. At demos, TMX consultants add the ice for a sorbet in two lots so the motor is not overstretched. Indeed, tonight when I made this recipe, I got an Error 34 and had to take some of the fruit out to get it going. Also, as was suggested by the recipe, you do need to assist with a vigorous spatula action. Even doing the sorbet in two lots, mine took way beyond the 45 secs suggested as a guideline.
At our cc, we add some coconut milk so it's not all iceblocks in the bowl. (Even having double the amount of lime flesh didn't help much to keep the revs down a bit.)
Another tip - make sure when freezing the rockmelon to use a big flat tray or even two, as if any of the blocks of frozen fruit stick together, you'll definitely have trouble with the motor revving or even shutting down.
So I'd give this 5/5 for taste and 3/5 for method -- sorry Alyce, but for this one, I was biased, due to having made so many sorbets in my Thermomix.