If I would of culled based on what judges say on juniors alone, then I wouldn't have many show rabbits left! I've had a multiple BIS animal hit dead last because the judge was scooting their hind legs to their eyeballs and then heavily faulting on ears???? I'm not sure what he was looking for lol but sometimes judges aren't experience and give crappy feedback! Some are excellent though and very helpful. IMPO Don't take a junior until it's about it's at least 41/2 -5 months because ,like MSD says, they just tell you it's promising unless it's a really bad animal that is poorly put together.
You also need to learn about your line, sometimes hot juniors fall apart, sometimes. ( like my line) things come with age (ex. Loin,heads, depth) ...usually my first cut is lack of width . A deep animal with no width comes with a price...usually = no loin. But a balanced animal that has equal width and depth looks a lot better overall.
You are paying for an opinion but listen for correlating comments.
Sometimes a promising jr doesn't always get the recognition it deserves among developed animals, but let them grow if down in your gut you know it's a good animal. I've learned to listen to my inner voice at times because I'll put them in a bottom home and in a month or two they have blossomed