Though the DS-to-Bryce bridge works, the way DS and Bryce handle materials - or shaders - are different and only partly compatible. You will have to adapt the material of all objects to make the best of them in Bryce. This can be very tedious, depending the objects used.
Bryce has an excellent renderer and outstanding lighting capabilities. A bit of getting used to is necessary, though. Luckily, there are many video tutorials by David Brinnen that help you getting acquainted with the process.
I’m not a very clever DS user but in my understanding, uber environment has nothing Bryce cannot do. Uber Environment2 is the DS answer to image based light (IBL) but in DS it is not correctly implemented and therefore of limited use. Bryce has one of the most advanced IBL implementations and it is very easy to use. There is no plugin for uber environment for Bryce because it is not necessary, Bryce has everything on board.