The Tobi Roppo designs were definitely better than their counterparts' who I supposed are the Veterans.
Not at all. There's nothing among the Tobi Roppo as smart as Oda playing with the idea of daifuku mochi being stuffed like a genie within its lamp (and how well said lamp is merged with Daifuku's body) nor as precise as how Perospero's design perfectly conveys its mischevous, talkative and wizardy idiosyncrasy (plus all the candy details) and even the small touches like the crown-like-parfait in Compote and Oven's mittens plus his oven signs-like hair and beard.
And, anyways, the Big Mom Pirates are way, way above the whole Beast Pirates in terms of designs. By far, it's not even close. Oda had the chance to play with a lot of inspirations from fairy tales, modern literature and fables and you can tell that. The man certainly enjoyed putting those designs together and even irrelevant characters like Bobbin or Diesel contain good ideas.
We should wait for their Zoan forms, though, because there's some potential play there. But so far they are way less stimulating in terms of design, they're either "cool-loking" in a simplistic way or even irreleavnt (Ulti is especially void, I've already forgotten her looks, and I just can't see the Page One we knew in his new human design). So far I have my hopes put in Black Maria (because of her visual rhymes and swords), Who's Who for the whole eyes theme and Sasaki to a lesser degree (thinking of his potential fruit and how his human traits could be implemented.
But again, I don't see any legit argument to put their designs above Big Mom's veterans's apart from the "cool" bias.