Welcome back to the craziness that is dart frog keeping! I will give you some of my opinions on your viv based on what I see and what I've read...
I think your viv looks great. I can tell you want a full and tropical look. I think your viv has great height and its a shame to see much of it not used. If you purchased some more driftwood or maybe even did the whole Great Stuff/silicon background thing, you could place broms or other epiphytic plants up there. I also noticed that most of your plants are self heading types. This means all they are gonna do is grow straight up towards the light. The Pilea (bottom right) will get very leggy and the oval leaved plant with white edges (a type of Peperomia) will get very very large and outgrow your viv. The Begonia (upper right corner) may rot on you but could come back. Those types also get very tall and leggy which is not always the most *attractive* thing to see.
Most of the other plants will do great and should look nice.
I don't think you really need more plants on the bottom but could definitely use some plants in the upper regions, especially bromeliads. With all that light, many of the Neoregelia types would color up fantastically. The one you have is a type of Guzmania which, oddly enough, like less light. Leaf litter is a definite must as well.
Again, welcome back and I hope my reply has been helpful somehow.