Planta is fantastic. Expensive, but that's what it aims to be. I've gone a few times for special occasions.
The hanging chairs near the front kept me entertained for a few minutes while I waited for a table the first time I was there. Most visits, however, didn't involve any wait. We were taken promptly to our table (arrived 5 minutes before reservations).
The decor is comfortable, modern, and balanced. I wish it were real plants along the wall, but I accept that's probably impractical.
The atmosphere is positive and energetic without being too loud to enjoy conversation.
Planta is a reliably great experience with interesting and tasty vegetarian fare. I'm skeptical of vegan cheese in general, but I don't hesitate at Planta - it's all great!