I've been watching several Ridley
matches and here are my impressions:
Ridley suffers pretty bad from big character syndrome. Although his
mobility isn't bad with 41st best air speed and 9th in run speed he doesn't have good ways to breach zoning/camping. He'll probably rely on Bair as it seems to be his best poke but even then it will be hard to contend with someone like Marth. Neutral is by far his worst state. Fireballs aren't very fast and too risky unless the opponent is offstage.
It looks like R was designed around gimping. He has midair jumps, a recovery with good distance, fireballs that drag down and of course his command grab is great at securing stage control. When intercepting he has a large presence, especially with ssbu's ultra laggy airdodges. His advantage state looks good but not broken.
Disadvantage is bad but not terrible for such a large character. He'll get juggled hard but has the weight to take it (although he's 1 unit lighter than Samus, wth?). Midair jumps help but he's basically charizard without the option to swap. Correct me if I'm wrong but R doesn't have any super armor to tank attacks.
If setups into his sweet spot tail thing and/or command grab are found it could really boost his viability. If not, he doesn't have much choice but to outplay the opponent with good reads. Ridley's weird in that his tools look OP yet seem highly impractical. He'll probably be a good scrub buster.
Overall Ridley seems underwhelming. Nothing's terrible about him but he'll have a hard time in neutral, a good but not OP advantage and bad but not horrible disadvantage. He lacks a good trump card.