I think it's be well worth the wait.

Bryce render can be slow, but then it depends on the processor/s, specially if you are using soft shadows, depth of field etc. Generally, a render is a bit like a box of chocolates......... i have waited an eternity for a render only to stop it and change my approach..... like, did I really need to use soft shadows here?
Still, I would keep it going if you are happy with it.
You could also try rendering a portion at a time, i've used this technique myself.
Anyway, good luck with the render, will look forward to viewing.