Porting Blender 2.79b projects into Blender 2.8

I have developed a fairly extensive library of complex objects in Blender 2.79b that I import (mainly as groups) and use in new visual compositions. (mainly as group instances)

With the arrival of Blender 2.8, I am keen to familiarise myself with the changes to the interface and to start using it as the default version. However, when I read some of the files created with Blender 2.79b ,viewport rendering does not appear to work properly. The objects are present but invisible.

Should I expect to be able to import objects (and groups in particular) from 2.79b.

A large part of my motivation in moving to 2.8 is support for collections. I would like to be able to create multiple (nested) collections and to control their visibility/editability individually in order to maintain control over very large scenes. Many of my projects, contain multiple group instances. I have heard that 2.8 is less efficient/reliable with respect to group instances. Is this true?

Do you think I am moving to Blender 2.8 too soon?